Screws

Screws

➤SKIP TO: TAPPING SCREWS | MACHINE SCREWS | SCREWS FOR PLASTIC | THREAD FORMING/THREAD ROLLING SCREWS | THREAD CUTTING SCREWS | SELF-DRILLING SCREWS | WOOD SCREWS | SEMS SCREWS

General Description:  Screws are used in a variety of industrial applications for assembling metal, wood and plastic products together. Over many years, standards such as IFI, SAE, ANSI and others have been developed, tested, and approved for worldwide use.

Generally speaking, most screws are available from stock, or with a very short lead time. These are known as general purpose or “standard” screws. For specific use or application (such as automotive PPAP), initial lead times are somewhat longer. These are known as custom or made-to-print parts and are designed specifically for the application.

Other proprietary or patented designs for high performance assembly are included. Benefits on an assembly line include ease of use, greater strength, improved corrosion resistance, etc.

Whether a screw is standard or special, there are unlimited choices for the design, including size, thread pitch, drive (recess) type, head style, material, heat treatment, plating and secondary operations (nylon patch, paint, etc). Fasco will assist you with the best options to solve your assembly problems.

Tapping Screws

A.K.A. sheet metal screws are threaded fasteners which tap / form their own mating internal thread when driven into preformed holes in wood, plastic or  metal. These screws are heat treated for strength and durability. They can be disassembled and reused. The predominant recognized standard is ASME B18.6.4.

DRIVE STYLES: Slotted, Phillips, Pozidriv, 1A, Frerson, Combo (Slotted + Phillips), Torx, Torx Plus, Autosert, Hexlobular, Start Drive, Hex, Flange, Socket, Allen, Square Drive, Robertson, Quadrex (Square + Phillips), Tamper Resistant, One Way, Spanner

HEAD STYLES: Flat (82°), Pan, Truss, Hex, Hex Washer, Flat (82° or 100°), External Torx, Oval, Round, Round Washer, Binding, Fillister

MATERIAL OPTIONS: Steel 1018, 1022, Alloy 10B21, SCM435, 4037, Stainless 302, 304, 316, 410, 430, A286, Aluminum 5056, 6061, Copper Alloys (Brass, Bronze, Copper)

PLATING OPTIONS: Zinc (Trivalent), Various Color Chromates, Zinc Alloys (Zinc, Tin, Zinc Nickel, etc), Passivation, Phosphate and Oil, Automotive Finish (Doerken, Magni, Etc), Proprietary Finish (Dacromet, JS-500, etc)

Machine Screws

Machine Screws are uniformly threaded screws designed to be threaded into uniformly mating threaded nuts (or threaded holes) in the parts they are intended to fasten. Typically available from micro sizes “00” (0.047) up to 3/8″ diameter (metric sizes also available). Shorter lengths are most common, but lengths can be up to 3″. Due to their relative size and strength, they can easily be differentiated from larger, stronger bolts. Additionally, driving (turning) the slotted or recessed head of the screw to tighten the fastening joint is common to machine screws.

A machine screw thread is defined by it thread size (diameter) and the number of threads per inch, followed by the thread form call out; “UNC” for coarse, “UNF” for fine, and the most common class of fit “2A” for external thread.

As the name implies, a machine screw is used to fasten various components together in machines, hand tools, white goods,  vehicles and many other applications. They are available in virtually any material, with the most common being steel, brass and stainless steel. The applicable standard is ANSI / AMSE B.18.6.3.

DRIVE STYLES: Slotted, Phillips, Combo, Torx, and External Hex are the most common. Other drive styles are available and can be made to order.

HEAD STYLES: Pan, Round, Truss, Hex, Hex Washer, Binding, Fillister

MATERIAL OPTIONS: Zinc, Zinc Trivalent, Nickel, Chrome, and Black Oxide are the most common. Other material options are available and can be made to order.

OTHER OPTIONS: Painted heads to match decorative or painted finishes
Adhesive locking patches to prevent loosening.

Screws for Plastic

Plastics have become an important part of industry over the last fifty years.  Improvements in technology resulted in hundreds of different plastics being created to serve a variety of purposes.  Earlier fastener thread designs for plastic – such as type B tapping screws or 25 (BT) thread cutting screws – were no longer suitable for assembly in the new plastic materials.  Not only did fastener manufacturers make improvements to existing thread designs, but they also developed many new concepts to solve the unique problems of joining plastics.

Over a generation some of these designs gained acceptance and approval from fastener consumers all around the world.  From among the most proven, successful designs, Fasco offers standard and customer variations of these products:  PT, Delta PT and Duro PT (originated by EJOT), Plastite, Remform (originated by Reminc), Hi-Lo / DST dual spaced thread (originated by ITW Shakeproof).

DRIVE STYLES: Phillips, Pozidriv, Torx, Torx Plus, and Torx Autosert are the most common.  Other drive styles are available and can be made to order.

HEAD STYLES: Pan, Pan Washer, Flat, and Oval.  Other head styles are available and can be made to order.

MATERIAL OPTIONS: 1018, 1022, 10B21, SCM 435 and 302 Stainless Steel

PLATING OPTIONS: Zinc (Trivalent), Zinc Nickel Alloy, and Passivated (Stainless).  Other plating options are available and can be made to order.

Thread Forming/Rolling Screws

Thread rolling screws were developed to solve many problems that arose as automation became an essential part of the assembly process.  The “need for speed” led manufacturing engineers to pursue new ideas for gaining efficiency and realizinig cost savings.  Thread roling screws were capable of rollforming their own threads into untapped holes.  Perhaps the most iconic design is the fully trilobular shape of the Taptite (Reminc) family of fasteners.  This unique patented thread design became the standard for high performance engineered fasteners by reducing friction during assembly.  The benefits included cost savings throughout the assembly process; elimation of thread tapping into the mating part becoming the most significant; and reduction in cross threading and anti-vibration / loosening were key features.

The new generation of Taptite products includes solutions to application specific challenges.  Examples include blind hole applications, assembly into die castings of various soft materials and self-locking screws which eliminate the need for secondary locking metholds like nylon patches.

Fasco offers the complete family of authentic TAPTITE products for use in metals and castings, including:  Taptite 2000, Taptite 2000SP, Taptite II, Duo Taptite and Powerlock.

DRIVE STYLES: Torx, Torx Plus, Torx Autosert, Hex Washer, Hex Flange, Phillips

HEAD STYLES: Pan, Button, Truss, Hex, Hex Washer, Hex Flange, Flat and Oval

MATERIAL OPTIONS: Boron Steel, Alloy Steel (Heat Treatment to suit application requirements)

PLATING OPTIONS: Zinc (Trivalent), Various Color Chromates, Zinc Alloys (Zinc, Tin, Zinc Nickel, etc), Passivation, Phosphate and Oil, Automotive Finish (Doerken, Magni, Etc), Proprietary Finish (Dacromet, JS-500, etc).

Thread Cutting Screws

When tapping screws are insufficient for an application, there are alternatives.  Thread cutting scrws are similar to tapping screws, but utilize one or more cutting edges and chip cavities to cut a mating thread into a pre-drilled hole.  Thread cutters are also a good alternative to thread forming and thread rolling screws when excessive stress or drive torque is inherent to the assembly.  Some thread cutting screws performed acceptably in plastic applications before other types of thread forms were developed.  This is still true today with certain designs.

Thread cutting screws are avialable from stock in certain sizes ranging from #4 diameter thru 5/16″ and up to 2″ in lenght.  However; countless option are available with relatively short lead times, including designs that are engineered to your specific application needs.

DRIVE STYLES: Slotted, Phillips, Pozidriv, 1A, Frerson, Combo (Slotted + Phillips), Torx, Torx Plus, Torx Autosert, Hexlobular, Start Drive, Hex, Flange, Square Drive, Robertson, Quadrex (Square + Phillips)

HEAD STYLES: Pan, Truss, Hex, Hex Washer, Flat, Oval

MATERIAL OPTIONS: Steel 1018, 1022, Alloy 10B21, SCM435, 4037, Stainles 302, 410

PLATING OPTIONS: Zinc (Trivalent), Various Color Chromates, Zinc Alloys (Zinc, Tin, Zinc Nickel, Etc), Passivation, Phosphate and Oil, Automotive Finish (Doerken, Magni, etc), Proprietary Finish (Dacromet, JS-500, etc)

Self-Drilling Screws

Self Drilling Screws were created in response to higher volume sheet metal applications. The threads are variations on either tapping (spaced) threads or machine screw threads; however, a drill point has been added to the tip of the screw. The purpose is to drill a hole through thin metal without the need of a pilot hole. It taps or forms mating threads without deforming its own thread or breaking during the assembly process. In order to accomplish these essentials, a special heat treat specification was developed which is now known as SAEJ78.

There are two methods for making the drill point on this type of screw. One is by milling (or cutting) and provides a very precise cutting angle on the screw. The drawback is that this a slower, more costly process. The alternative is a forged point (also known as a pinched point) which is faster to produce; however, it is limited in certain applications because it is less precise than the alternative method. The length of the point is determined by the material that must be penetrated by the drill tip.

The most popular brand is known as the TEK screw and was developed by ITW. The original patent has expired and the term “self drilling screw” and TEK have become interchangeable.

DRIVE STYLES: Robertson

HEAD STYLES: External Torx

Wood Screws

Wood screws are coarse-threaded non heat treated fasteners used to assemble wood to wood or laminates. Preformed holes are recommended. Easily recognizalbe by the unthreaded shoulder and partially threaded shank. Sizes range from #2 through 1/4″. The recognized standard is ASME B18.6.1.

DRIVE STYLES: Slotted, Phillips

HEAD STYLES: Pan, Flat (82° or 100°), Oval, Round

MATERIAL OPTIONS: Steel (low carbon) and Brass

PLATING OPTIONS: Zinc (Trivalen), Various Color Chromates, Black Oxide, Brass, Bronze and other Decorative Finishes

SEMS Screws

SEMS are threaded fasteners which combine and captivate one or more washers onto a screw. They are assembled with speed and precision, eliminating costly hand assembly and improving production efficiency and quality. The screw and washer are permanently attached, but the washer remains free spinning.

Virtually any type of screw (Tapping, Machine, Thread Cutting, etc) can be combined with a variety of washers to suit any application. Sizes range from #2 through 3/8″ (M2 through M10). The applicable standard is ANSI B18.13.

Washer Types available for SEMS: Tooth (Internal, External and Combination), Helical Split, Flat, Conical, Terminal and Proprietary Designs (Square Cone, Split / Flat Combo).

DRIVE STYLES: Tamper Resistant, One Way, Spanner

HEAD STYLES: Round