Metric Screws

Metric Flange Screws are also referred to as flange bolts and frame bolts. The non-serrated flange, which is larger than the hex head width, provides a smooth bearing surface and distributes clamping force over a greater area so they can be used with oversized holes. These screws are supplied with coarse machine screw threads.

Metric Hex Head Cap Screws are extremely common and generally considered to be fully threaded. They otherwise have a hex head and coarse or fine machine screw threads, which makes them the same as Tap Bolts and similar to Hex Bolts, Hex Head Bolts and Machine Bolts, all of which are partially threaded.

Metric Machine Screws encompass a family of small screws, which are much smaller than what most consider to be bolts—M10 and smaller are common although some M12 and M16 sizes may be available. Suitable for light-duty, low-torque applications, they include Cheese, Flat, Oval and Pan Heads and Phillips, Pozi and Slotted drive styles. Coarse machine screw threads are standard.

Metric Set Screws are headless and fully threaded with coarse machine screw threads—except for their point—and are internally wrenched. Typically recessed in the collars of gears, knobs and pulleys, they are sometimes used to fasten assemblies. The different point styles—Cone, Cup, Dog and Flat—offer different advantages in permanent and semi-permanent applications. Use in compression since tensile loading is not recommended. They are also referred to as Allen Screws and Grub Screws.

Metric Shoulder Screws are also called Shoulder Bolts. The precision shoulder is used as stripper spring guides, clevis pins, pivots, shafts and spacers. The hex socket head is larger in diameter than the shoulder, and the coarse machine screw threaded tip is smaller than the shoulder. They are also called Stripper Bolts and Axle Bolts.

Metric Socket Cap Screws include Button, Flat, Low and Socket Heads. All are internally wrenched using a hex key or hex bit, which allows for close spacing and recessed mounting. Unlike inch series, metric Socket Head Cap Screws are available in three strength grades so be sure to match the Class (strength grade) when replacing screws. Also, Class 10.9 (and higher) Button, Flat and Low Head screws are not rated for high-strength applications, as specified by ISO 898-1, but wear resistance of the hex socket recess is improved. Button, Flat and Low Head have coarse machine screw threads; Socket Head has coarse and fine threads.

Metric Thread Rolling Screws have a trilobular shape that forms (rolls) threads and simultaneously work hardens the mating material without creating chips as they are driven into a pilot hole. Despite low installation drive torque, a fastened joint with superior prevailing torque is created that is resistant to loosening caused by vibration. They have coarse machine screw threads.