Inch Shoulder Screws

Precision Shoulder Screws, also known as shoulder bolts, are fasteners with an unthreaded cylindrical section, or shoulder, between threads and screwhead. The shoulder is larger in diameter than the threaded section and provides an axis around which close-fitting moving parts operate.

Precision shoulder screws are available with an undercut shoulder where the diameter of the shoulder can be as small as the minor diameter of the threads. Precision shoulder screws are identified by the diameter and the length of the shoulder.

Precision shoulder screws can be produced with a slotted or hex socket head. Precision shoulder screws differ from standard shoulder screws in that they have very tight dimensional tolerances. Precision shoulder screws are typically available in stainless steel but can also be made from alloy steel and brass.

precision shoulder screw Notes:
1. Thread Length Tolerance: -0.020in. for sizes up to 3/8 in., inclusive, and -0.030 for sizes over 3/8 inch.

2. Concentricity: Head shall be concentric with the shoulder within 1 percent (2 percent total runout) of the nominal diameter D or 0.003 inch (0.006 inch total runout), whichever is greater. Concentricity, parallelism, bow and squareness of shoulder to thread shall be within 0.005 inch total runout per inch of shoulder length, with a maximum of 0.025 inch, when firmly seated against the shoulder in a threaded bushing, and checked on the shoulder a distance of 2F from the underside of the head. Threads of bushing shall be basic size, and busing OD and ends shall be concentric and square with the axis.

3. Bearing surface: The plane of the bearing surface of the head shall be perpendicular to the axis of the shoulder within a maximum deviation of 2 degrees.

We carry both inch and metric standard sizes.

Bay Shore, New York 11706 631-517-0645

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