Slotted Pan Head Machine Screws Zinc Plated Carbon Steel Coarse Thread For Industrial Equipment Assembly
Shoulder screws are precision fasteners with three distinct parts. The head, the smooth ground shoulder, and the threaded end. The shoulder acts as a rotating shaft or precision spacer while the thread provides secure mounting.
How They Work
The shoulder is ground to a precise diameter with tight tolerance. This smooth surface allows bearings, bushings, gears, and pulleys to rotate freely. The threaded end screws into a tapped hole or nut to hold the assembly in place. When you tighten the screw, the head controls how far the shoulder goes into the mating part.
Head Styles
Pan head is the most common for flush mounting applications. The flat top and flat underside provide even clamping pressure.
Hex socket head shoulder screws have a hex drive for high torque tightening. Good for tight spaces where a wrench cannot fit.
Hex head shoulder screws work with standard wrenches or sockets. Good for larger sizes and higher torque applications.
Flat head shoulder screws sit flush with the surface. Good for countersunk applications where a smooth finish is needed.
Headless shoulder screws have no head. The entire screw is shoulder and thread. Good for applications where both ends need to be flush.
Phillips head shoulder screws work with standard cross tip screwdrivers. Good for general assembly where high torque is not required.
Materials
Stainless steel 304 shoulder screws offer good corrosion resistance for general industrial use. Stainless steel 316 provides excellent corrosion resistance for marine and chemical environments.
Alloy steel Class 12.9 offers high strength for heavy duty applications. Carbon steel Class 8.8 and 10.9 provides cost effective strength for general use.
Shoulder Specifications
Shoulder diameter from 2mm to 25mm. Shoulder length from 2mm to 150mm. Shoulder tolerance as tight as h6 or h7. Surface finish ground to Ra 0.8 or better.
Sizes
Metric M1.6, M3, M4, M5, M6, M8, M10. Standard shoulder lengths from 3mm to 100mm. Custom lengths and diameters available for OEM orders.
Where People Use Them
Jigs and fixtures. Mold guide pins and bushings. Bearing shafts and pivot pins. Conveyor rollers and sprockets. Cam followers and linkage assemblies. Printing and packaging machinery. Medical devices. Food processing machinery.
Custom Shoulder Screws
We accept custom orders for special shoulder diameters, lengths, head styles, and materials. Send us your drawing or sample. Fast prototype service. Factory direct pricing.
Quality
All shoulder screws undergo thread gauging and dimensional inspection. Precision ground shoulder with tight diameter tolerance. Class 8.8, 10.9, 12.9 options. Custom shoulder length and diameter per drawing.
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Precision ground shoulder acts as shaft or spacer
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Tight diameter tolerance for smooth bearing rotation
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Hex socket head hex head flat head headless styles
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Stainless steel 304 and alloy steel Class 8.8 to 12.9
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Custom shoulder length and diameter available
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OEM orders welcome
Established in 1998, YH Fastener is a high-tech enterprise integrating R&D, production, and sales. We serve clients including Xiaomi, Huawei, and Sony across industries such as 5G, aerospace, electronics, and automotive parts. Our precision fasteners meet GB, ANSI, DIN, JIS, and ISO standards. ISO9001, ISO14001, and IATF16949 certified. 28 years of experience. Custom and OEM orders welcome. Factory direct.
For inquiries, please send us your drawing or sample. We will reply with a competitive quote within 24 hours. OEM and custom orders welcome.
