1. ; Outside angle ferrule – Used for the opposite side of the inside angle ferrule. Unless stated otherwise, all threaded studs are reduced base (Type RD). Add to Cart. Preliminary experiments focused on stud welding parameter optimization. With the Arc process, you obtain a full fusion weld that. Electrodes for Shielded Metal Arc Welding 11th Edition Revises AWS A5. The welding gun fires the stored electricity through the weld stud and melts the tip or projections into the base material. Choose from our selection of weld studs, including over 175 products in a wide range of styles and sizes. Distributor of welding equipment including welding studs, arc welding studs & capacitor discharge (CD) welding studs. By using flanged CD weld studs, a strong bond between the base material and stud is created. If you don't see the stud you need, give us a call at 800-426-5667. assumes no financial or physical responsibility for damage or harm resulting from this information’s use with non-Nelson studs and related accessories. 50 USD. On sc. ©2023 Monroe JHP Fasteners, Inc. Nelson ® offers a complete line of portable and feed stud welding systems to meet even the most demanding of stud welding performance requirements. 3. 00 USD. 39 USD. A CD stud can be shot to the attachment side without reverse-side marking, unlike traditional fabrication methods that require drilling a hole to insert a bolt for an attachment point. The stud is placed (with a hand tool called the Weld Gun) against the base metal, through the control of the stud welding equipment and the design of the stud; an arc Specify. 2 mm). Arc stud welding is a process by which a metal fastener is welded to a parent metal through a fusion weld. 00 USD. You can use either a capacitor discharge or a drawn arc capacitor discharge technique. A complete line of Stud Welding Equipment and. Capacitor Discharge (CD) Stud Welding is a semi-automatic arc welding process. 4 Gas Metal Arc Welding (GMAW) 23 2. In stock and ready to ship. Aluminum Arc Full Base (FB) Weld Pins. Nelson ® Studs & Equipment. For example, the Proweld ARC-3000 can weld studs from 1/4″ to 1-1/4″ diameter with preciseness and repeatability. The best aluminum studs have a built in ignition tip that burns away before the weld is performed. 7/8. 5% of the 7A52 aluminum alloy base material in tensile and shear tests, respectively, which solves the problem of. 6-32. Browse Collar Arc Weld Studs in the Midwest Fasteners, Inc. Choose from our selection of weld studs, including over 175 products in a wide range of styles and sizes. 9 : Automotive spot weld testing. Studs 5/8" (16mm) diameter and above will be approximately 3/16" (5mm) shorter after welding. 800-426-5667. Lengths range from 16-100mm (mild steel and stainless steel). The welding stud is then forced into the melted area and held in place until the metals re-solidify. Weld studs are threaded fasteners that take less time to install than fasteners that require drilling, tapping, punching, or screwing. Metal arc welding is particularly suitable for welding heavy sections, and can be used for welding thicknesses up to 2-1/2 inch (63 mm thick). Tip ignition, drawn arc, CD (capacitor discharge. Welding tools for automized applications. If you don't see the stud you need, give us a call at 800-426-5667. 1) The weld gun is positioned over the base material and the main gun spring is partially compressed. Arc stud welding joins the base (end) of the stud to the work-piece by heating the stud and the work with an arc drawn between the two. Weld Stud diagrams, specifications and materials are provided for each model. The studs pictured do not represent a complete listing of all possible styles of studs that are in stock or available. Stud Welding Low Carbon and Austenitic Stainless Steels 17 6. It is a single-step process for creating a strong joint between metal surfaces that incorporate weld studs as fasteners. Drawn arc stud welders connect to compatible drawn arc stud welding guns and supply current to weld studs held in the guns. Unthreaded studs are full base (Type UD) unless a smaller base is. Posted in Arc Welding, CD Stud Welding, Stud Welding Supplies. Some weld fastener options include weld nuts , weld studs, and weld pins. Stud welding. 5/16-18 CD Weld Stud, Flanged, Stainless Steel from $12. Next, aim the stud gun where you would like to install the pin. The CD process is commonly used in most sheet metal shops. Our company is a Private Limited, which has settled its main head office at Pune, Maharashtra from where all the business related activities are keenly monitored by skilled professionals. Fixed, secure contact and load capacity over a number of years even at. Stud welding is a complete one-step fastening system, using fasteners called weld studs. 02 USD. 55,000 psi (min. An electric arc is created between the end of the stud and the surface of the workpiece, melting both parts. Abstract: In this paper, the influence of two selected parameters (the welding time and the presence of the activating flux on the surface of the base metal) on the weld joint at Stud Arc Welding process is investigated. Small Split Bipod Nelson NS30/NS40 Foot $155. They do not lose any length during the stud welding process and are suitable for use on sheet metal and other thin materials that would be marred by the drawn arc welding process. Aluminum stud welding is performed with conventional stud welding equipment. Refer to AWS C5. The fastener can be threaded, unthreaded, tapped, and so on. For gas metal arc welding, the wire is classified using 100% CO 2; however, argon-oxygen-carbon dioxide combinations may be used based on the oxygen equivalent. 4-40 CD Weld Stud, Flanged, Aluminum from $4. Proper arc length is paramount, and CV power sources help maintain that constant arc length. Taylor Studwelding stock low carbon, mild steel weld studs for drawn arc and. 5. shows current, white shows arc voltage variations within the 900 msec needed to complete a weld. 4008 COMPLEtE STUD WELDING Products •Service •Knowledge •Integrity 4. Deciding which to use depends on weld requirements, materials, and applications. Drawn arc stud welding operations are used extensively in the construction industry. The terms “stud welding” and “shear stud” are commonly used in the process of attaching steel frames to composite floor constructions. 281. Stud welding, also known as drawn arc stud welding and arc welding, is the action of welding a shear stud to a metal object, for example, a metal deck. Stud welding is a process of joining a metal stud to a metal workpiece by heating. The two general types of stud welding are drawn arc stud welding and capacitor discharge (CD) stud welding. As the drawn arc current heats the tip of the stud and the metal becomes molten, the ring-shaped ferrule keeps the metal from spreading into a messy weld. catalog including Flanged Capacitor Discharge (CD) Studs - Imperial,Flanged Capacitor Discharge (CD) Studs - Metric,Small Flanged Capacitor Discharge (CD) Studs,Non Flanged Cap. The welding stud is then forced into the melted area and held in place until the metals re-solidify. For hot-dip galvanized steel, the same process can be performed, but the end results are somewhat different. Stud welding is a process that involves welding a metal fastener to another metal part using an arc of electricity to heat both parts. Some weld fastener options include weld nuts , weld studs, and weld pins. 00 USD. Arc stud welding is a process by which a metal fastener is welded to a parent metal through a fusion weld. That’s why our facility specializes in quick-turnaround build-to-print stud welder services. Cutlass Stud Welding. Weld studs are threaded fasteners that take less time to install than fasteners that require drilling, tapping, punching, or screwing. Process different studs with. Beckham Chrysler LLC R. comWeld Studs Bolt. Arc studs are typically loaded with an aluminum flux ball on the weld end, which aids in the. No filler material is needed, only a little bit of pressure. Arc를 발생시켜서 용접을 시행하는 점에 있어서는 일반적인 SMAW와 유사한 점이 있으나 연속적인 용접 Bead를 형성하지 않는 차이점이 있다. Using a “ferrule” to capture and retain the weld’s heat, the molten metal created by the process cools the weld site and produces a weld that is stronger than the stud itself. Contact us for more information regarding our high-end weld screws and studs or call us at 800-783-0910, we. When triggered, an electric solenoid in the gun lifts the stud to a preset height off the base metal. A. Arc Studs are manufactured. Proweld Arc Gun Body $619. When theModes of Metal Transfer Preferable to Aluminum Welding - Globular-to-spray transition currents. Length: Length is before weld. Quantity. You can use either a capacitor discharge or a drawn arc capacitor discharge technique. Arc stud welding creates strong, one-sided welds on base metals as thin as 0. The CD process operates on the principle of capacitor stored energy which is. D. With drawn arc stud welding, the operator uses a weld tool, or gun, to place the stud against the base metal. These unique fasteners feature durable threads with proven reliability, saving significant time and money over hand welding processes. Unthreaded studs are full base (Type UD) unless a smaller base is. Drawn Arc Stud Welding explained. E. A stud is loaded into a compatible CD. A complete line of Weld Studs for all types of applications: Capacitor Discharge (CD), Arc and Drawn Arc. TF studs permit close run down of a nut to the base metal. 3 Automatic Feed Systems 17 6. Weld Studs join a stud and another piece of metal together by heating both parts with an arc. Stud welding is a process where a metal clasp is welded to another metal component using an electrical arc to heat the parts. In particular, it is an established joining technique for large studs in steel construction. The CDS10M Capacitor Discharge Stud Welder is uniformly welded, of high quality, and has no traces on the back of the. For welding up to 1/4" (6mm) diameter CD weld studs in aluminum and 5/16" (8mm) in mild and stainless steel. 00 USD. Ferrules are supplied with the studs. 8. Save money on your stud welding accessories! Replacement accessories and parts for your Nelson NS20, NS30 or NS40 stud welding gun. 06 seconds. With GTAW, DC- polarity results in more weld penetration. 2. 25 USD. Sunbelt FB aluminum studs, available in diameters from 1/4" to 1/2", have equal weld base and thread diameters. A. 10 ELECTROSLAG WELDING:. Will be approximately 1/8" shorter after welding. Perfect for drawn arc stud welding--weld fasteners to dissimilar parent metals efficiently through arc stud welding. 3% and 118. Our team of stud welding experts has years of experience providing manufacturers and welders with several products to meet their welding needs. Tensile and Torque Strengths: The 2 charts – Standard ARC Welding Studs – Tensile /. Material: Aluminum alloy 5000 Series. It is a mechanized welding process Drawn Arc Stud Welding explained. Nelson ® offers a full line of standard in-stock fasteners for quick shipment, as well as custom-designed fasteners to meet your specific needs. Each of these applications requires the proper style stud and ferrule, so please specify your application when ordering. 4. 5/16-18 CD Weld Stud, Flanged, Mild Steel from $9. 07 USD. Stud welding. MECHANICAL PROPERTIES. Available with weld-base diameters from 5/16 inch through 1/2 inch; thread diameters as specified. Metric Left-Hand ThreadedLow-Strength Steel Threaded Rods. This process can be used for a variety of applications, from industrial manufacturing to construction. Tucker® weld studs offer a secure hold for everything that needs to be fastened. Metal fasteners for Construction, Oil Field, Insulation Installation, Aerospace, Signs, Transportation and many other industries. Aluminum 10-24 Flanged CD Weld Studs - CDF0102424A. Member Price: $169. AWS D10. For welding up to 5/8" (16mm) diameter ARC weld studs in mild steel, stainless steel, and aluminum. Thread Size. Stud Welding. 800-426-5667. An aluminum base with aluminum studs is the best way to go. For hot-dip galvanized steel, the same process can be performed, but the end results are somewhat different. The process can quickly weld almost any size or configuration of metal stud to a workpiece, with maximum weld penetration and reliability. Once the weld has cooled, the ring is broken away, leaving behind a smooth fillet at the stud's base. Sunbelt FB aluminum studs, available in diameters from 1/4" to 1/2", have equal weld base and thread diameters. ‘Stud welding’ and ‘shear studs’ are terms often used in connection with steel frame and composite floor construction. 8. 3/8-16 Arc Stud, Partial Thread, Mild Steel with P Ferrules from $18. 3/8-16 CD Weld Stud, Non Flanged, Mild Steel. The drawn arc. Tensile. 20 USD. Arc stud welding creates strong, one-sided welds on base metals as thin as 0. With GTAW, DC- polarity results in more weld penetration. CD (capacitor discharge) weld studs require lower levels of heat and less time to weld than drawn arc weld studs. Our stud welding experts can see if we have it or find it for you. Box: 16101,RAK Free Trade Zone,Ras Al Khaimah, U. Drawn arc weld studs form strong, vibration-resistant welds that provide a tight seal against water. 2 Gas Metal Arc Welding (GMAW). Arc stud welding utilizes a DC power supply to create the arc, a stud welding tool, metal fasteners, and in some cases, ferrules. Drawn arc stud welding joins a stud and another piece of metal together by heating both parts with an arc. 1 Arc Stud Welding. Made in the USA. stud welding fastners wear abrasion stainless steel tuffstudds Tuff studs anchors rentals sheer connectors nelson keystone atlanta stud welding rentals capacitor dischaege arc. There are a wide range of spot weld stud and tab weld stud options, depending on the specific application. Arc stud welding is a highly dependable attaching method that may be used in a wide range of applications. A. 048 inch. Some types or styles of weld studs are used in the imperial size when. - Flux core arc welding on plate. (4. @article{osti_20014308, title = {Drawn arc stud welding: Crossing over from steel to aluminum}, author = {Ramasamy, S}, abstractNote = {In their quest to reduce vehicle weights, car manufacturers are exploring further use of aluminum, including more aluminum components in body construction. 25 x 18 Arc Stud Full Thread Nickel Plated with LP Ferrules from $36. 2. Save money on your stud welding accessories! Replacement accessories and parts for your Nelson NS20, NS30 or NS40 stud welding gun. By using flanged CD weld studs, a strong bond between the base material and stud is created. 1/4-20 CD Weld Stud, Flanged, Mild Steel from $8. Arc Gun Connector Stud 10mm $25. Typical Use: Heat transfer pins. Conforming to industry standards, practices and procedures, the competency-based Welder Foundation program provides you with the skills you'll need to prosper in today's job. 10-32 CD Weld Stud, Flanged, Stainless Steel from $10. Shielded metal arc welding (SMAW) and tungsten inert gas (TIG) welding are widely used with different electrodes or filler wires to find out the optimal outcome for dissimilar material joining [8]. Proweld LD Arc Gun Front Cap $34. I tried this method but the finishing was not good. AWS D8. D. Uniformity and Repeatability - the stud welder precisely controls and monitors the amount of energy used to weld the fastener which produces consistently strong welds. Made in. A nationwide supplier with overnight deliveries available. Arc studs may be almost any shape and there are literally hundreds, however, they must have one end of the fastener designed for arc welding. They do not lose any length during the stud welding process and are suitable for use on sheet metal and other thin materials that would be marred by the drawn arc welding process. Adapter Screw 21. If you wish to see design specifications, special application procedures, and part number information for a particular category of fasteners, choose from the available selections below. Threaded studs are available in M6, M8, M10, M12, and M16 diameters. For a quick visual of how this is done and how simple it. Available with weld base diameters from 1/4” through 1/2”; extension diameters, 1/8”' through 3/8”. Sunbelt stocks a wide assortment Arc, CD, Refractory, Aluminum and Military Grade Weld Studs. It is suitable for welding applications on thick materials that require. In the stud welding industry, shielding gas is typically used with drawn arc welding to replace the need for a flux and ferrule ring system. STUD WELDING STORE. Stud welding is also used for the fabrication of steel structures. General Information for Stud Welding Studs Aluminum Nelson manufactured aluminum studs are made from Aluminum Association (AA) alloys 5356,. 5/16-18 CD Weld Stud, Flanged, Mild Steel from $9. Home > Weld Fasteners > Arc Weld Fasteners > Full Thread Arc Weld Studs – Inch / Metric > 1/2-13 Full Thread Arc Weld Studs - Inch / Metric. The stud itself becomes part of the weld material. Every day, millions of welding studs are joined via stud welding processes in many areas of the metal industry. 1/4-20 CD Weld Stud, Flanged, Mild Steel from $8. Complete Stud Welding TF weld studs are available in mild steel and stainless steel materials. Our stud welding experts can see if we have it or find it for you. ; Inside angle ferrule – Used when mounting the stud to the inside of a 90-degree angle, such as the insider corner of heavy angle iron. Welding. Sunbelt aluminum collar studs are partially threaded studs with a collar separating the weld base and thread. Chucks, Ferrule Grips, Legs, Feet, Foot Plates and More. Capacitor Discharge (CD) Stud Welding is a semi-automatic arc welding process. Therefore, the general procedure and requirements based. The process is as follows: The weld stud is places against the base metal. The right arm of your SWS system. Stud welding equipment is available for sale or rental in capacities from 1/4 in. Summary. They are available in thread diameters from 1/4" through 1/2". 47 USD. Stud welding uses direct current electricity to create an arc between a fastener or stud and the parent material. Arc Gun Accessories for Welding ¾’’ diameter Weld Thru-Deck Studs: Extension Legs B-0109-18 18” Foot Piece B-0021 Foot Extension Assembly Grip B-0060-1 Chuck Ch-075. The polarity used in stud welding depends on the type of metal being used. Most of our studs are designed to be installed. 50 USD. 25 USD. 3/8-16 CD Weld Studs. 800-426-5667. Our stud welding experts can see if we have it or find it for you. 32. Ph: +971. Arc studs come in many shapes, and there are literally hundreds of kinds—as long as one end of the stud is designed to be compatible with an arc welder and is made of weldable materials (mild steel, stainless steel, or aluminum), it can used for arc stud. CD Weld Studs. Understand the differences. The chart below indicates the weld studs commonly supplied in metric sizes. About. *Weld current should be checked by using a time current monitor. Arc Stud Welding Arc stud welding is a highly reliable fastening method for a wide variety of applications. It is one of the many types of welding available to professionals across the engineering, construction, and manufacturing industries. 6-32 CD Weld Stud, Flanged, Aluminum from $4. If you don't see the stud you need, give us a call at 800-426-5667. 21 USD. This tip provides accurate welding time control with precise repeatability. View Volume Discounts. View drawn arc stud welding and headed weld studs applications, dimensions, standard & torque specifications How strong is a stud weld? Steel with a low carbon content that has a minimum tensile strength of 60,000 psi, a minimum yield strength of 50,000 psi, and an elongation in 2 inches of at least 20%. However, with CD welding small diameter fasteners (1/4″ and under) are end welded to extremely thin gauge parent metal. The first application was to secure wood decking on submarines, but was quickly adopted and used on battleships. The right arm of your SWS system. Annealing - Sunbelt arc welding studs can be annealed to a maximum of 75 Rockwell B for low carbon steel; 90 Rockwell B for stainless steel. Start the arc on a scrap piece of copper or aluminum and watch the end of the electrode form a ball. 10-24 CD Weld Stud, Flanged, Aluminum from $8. 3 Welding Technique for Steels 18 7. Weldstuds for Grounding. Stud, Ferrule & Accessory Catalog . Over 1000 sizes of threaded, no thread, tapped, and stored Arc weld studs. It permits strong, one-sided welds on base metals with thicknesses starting at 0. The process is characterized by its high heat input due to high current and a weld pool protection realized by a ceramic ferrule holding the metal vapor. Cannot be welded to galvanized sheet materials and common aluminum alloys. Stud welding by lifting the stud to a predetermined height above the base metal. 00 USD. 4M:2006 Prepared by the American Welding Society (AWS) A5 Committee on Filler Metals and Allied Materials. ARC is generally used for stud diameters of 1/4" and above and when welding to thicker base materials or in structural applications. Arc Weld Studs; Capacitor Discharge (CD) Weld Studs; Refractory Weld Studs; Military Grade Weld Studs;. An Overview of Plasma Arc Cutting of Aluminum - comparison of plasma arc, laser and water jet. The stud welding process is applied to increase the quality of the welding joint for the parts. Primarily, spot welding is used with low-carbon steel, but it can be used to form brittle connections with high-carbon steel and aluminum alloys. have been included. Nationwide Toll Free: 1-800-252-1919. Schematic of composite metal deck concrete floors. Stud Welding Practices & Procedure - PFSNO. Insulation fasteners for welding come in many different types such as cup head weld pins, double-pointed pins, self-locking washers and speed clips, lasing anchors, adhesive and non-adhesive backed pins. Typical Use: As a spacer between parent metal and part secured on extension. Accessories: For required accessories, please see each specification page or contact your CSW representative for assistance. 847-228-1995 FAX. What is Stud Welding. 1157 Pagni Drive. These weld studs are well suited for welding to sheet metal grade material. Contact us for more information regarding our high quality ring weld projection stud fasteners or call us at 800-783-0910, we would be happy to assist you with any questions that you may have. Very short set-up time (a. A calculated current and weld time is triggered to create a pilot arc as the stud lifts to a pre-set height. The materials we use are suitable for important relevant EN and ISO industry standards; for example, our aluminium studs are EN 573-3 compliant and our stainless steel CD studs comply to. Material: Aluminum alloy 5000 Series. An assessment of the material properties in specific weld zone regions is not requested under consideration of their limited areas or the general joint dimension although the. Learn more about engineering specifications in the stud welding industry with Northland Fastening Systems. IWT S1 Extended Reach CD Gun $985. CD Weld Studs. 14 : Automotive arc welding aluminum. CD weld studs, or capacitor discharge weld studs, are small diameter fasteners joined to thin sheet metal. 1/4-20 CD Weld Stud, Flanged, Mild Steel from $8. 4-93"Weld Studs join a stud and another piece of metal together by heating both parts with an arc. CD (capacitor discharge) weld studs require lower levels of heat and less time to weld than drawn arc weld studs. Ferrules - All orders include ferrules when required. 외형상으로는 전기. electric arc is the major factor that is used to melt the metal employing the pressure on the joint area for a short time. Set Screw - #8-32 x 1/4 $0. Weld Studs are installed using a drawn arc stud welding gun to. 048 inch. First, insert the insulation pin into the stud weld gun. With shielding gas, welders can eliminate potentially porous welds prone to corrosion. C. To learn more about fastening systems and our stud welding supplies and services, contact Northland Fastening Systems at (651) 730-7770. A closer look at DA The drawn arc process is used when larger diameter studs or bolts are welded to thicker, uneven, or dirty base materials. Arc studs reduce in length when welded. comIn general, we recommend flanged CD studs for diameters up to 5 ⁄ 16 " and flanged CD studs for 3 ⁄ 8 " diameter studs. 73–108. S. Because of its pace, precision, and the efficient results it produces, many prefer the. 19 USD. 92 USD. The ordinary stud welding gun has slight modifications done to it to facilitate welding of aluminum studs. Available for steel and gas-supported welding like Aluminum. There are a wide range of spot weld stud and tab weld stud options, depending on the specific application. CD weld studs can be used with thin base metals and. Arc stud welding is commonly used because it can used with sheet metal. 70 USD. Complete Stud Welding TF weld studs are available in mild steel and stainless steel materials. Welding can be done with many processes such as arc, resistance, friction, and percussion. Links: Spec Sheet Manual. The ball should never be more than 1. Sunbelt aluminum standard studs are partially threaded with a weld base diameter greater than the thread diameter. PFS's CD weld studs range in diameter from 4-40 to 3/8, and are manufactured from AISI 1006-1020 low-carbon steel, 300 series stainless steel, copper alloy 260 and 268, and 1100, 5000, and 6061 series aluminum alloy. Arc welding is commonly used for joining aluminium alloys. Some common mistakes with Block 2:Automotive arc welding of steel. Stud welding is also known as drawn arc stud welding , or arc welding for short. manual metal arc, has been left to the discretion ofthe deslgner-c) The allowable stresles in welda have been increased to bring them in line with thOle for parent meta) given in IS: 800-1962-. Using a “ferrule” to capture and retain the weld’s heat, the molten metal created by the process cools the weld site and produces a weld that is stronger than the stud itself. Drawn arc stud welding (SW) is a welding pr ocess whereby a metal fastener (i. A weld stud can be end-joined to a metal work piece instantaneously for a high. Spot welding has limited uses because it works well with few materials. Process different studs with. Using a “ferrule” to capture and retain the weld’s heat. The gun then forces the stud down into the molten. Our stud welding experts can see if we have it or find it for you. Stud welding is the process of welding a shear stud to another metal object. Arc stud welding is a process by which a metal fastener is welded to a parent metal through a fusion weld. 12: Pipe welding (mild steel). Weld Studs. 00 USD. In stud welding, the power source and stud welding control system are set to con-trol the amperage and the arc dura-tion or time. Arc Stud Welding utilizes a DC power supply to create the Arc, a stud welding tool, metal fasteners, and in some cases, ferrules. 092 0014 10. The presence of zinc and included zinc vapors in the weld can weaken the weld to the point of failure; however, the practice of stud welding on galvanized steel remains very common. Install them using conventional welding or specialized stud welders; a ferrule is included for use with stud welders. AWS D9. 5/16-18 CD Weld Stud, Non Flanged, Stainless Steel from $67. 030 inch, in Keystone Fastening Technologies - OBO Bettermann catalog for capacitor discharge process. the names Stored Arc or Tranquil Arc in the text are references to the Stored Arc stud welding process or Tranquil Arc accessory kit, as defined by Nelson Stud Welding, Inc. Our complete catalog is available for online ordering. We are the #1 manufacturer of choice. 00 USD. Uniformity and Repeatability - the stud welder precisely controls and monitors the amount of energy used to weld the fastener which produces consistently strong welds. These metric threaded rods tighten when turned to the left; once fastened, they resist loosening from counterclockwise motion. Materials include steel & stainless steel studs.