ISO 7379 Hex Socket Head Shoulder Screws
ISO 7379 hex socket head shoulder screws M5 to M20 — precision shoulder bolts with f9 ground shoulders for linear and rotary motion — with the full collected 7-size table: shoulder tolerances, thread length, plain/knurled head geometry, key engagement and shank data.
Last updated: 2026-11
Specifications
ISO 7379 is the shoulder screw built for motion duty: a precision-ground unthreaded shoulder (d s, toleranced f9) carries the rotating linkage, cam follower or sliding guide, while the threaded end clamps it into the housing. The shoulder is the bearing surface — not the threads — so its tolerance band and finish are what separate a shoulder screw from a regular cap screw with a long grip. The collected table spans the standard series M5 to M20 and reads as the machine-design data sheet it is: shoulder diameter d s with its f9 max/min limits, thread length b (max/min), head diameter d k printed separately for plain and knurled heads, head height k, socket key width s and engagement t, the g 1/g 2 transition geometry, thread blank d s1, across-corners e and the under-head fillet r min. The f9 shoulder slides in a reamed or bored hole with defined clearance — mount two on parallel arms and both pivot without wobble. For the inch-series counterpart see the ASME B18.3 shoulder screw page on this site, and for the slotted small-size variant DIN 927.
| Standard | ISO 7379 — hexagon socket head shoulder screws (metric) |
|---|---|
| Series | M5, M6, M8, M10, M12, M16, M20 (7 sizes tabulated); shoulder diameter runs larger than the thread — e.g. 6.5 mm shoulder on M5 |
| Tabulated geometry | Per size: pitch P, shoulder d s f9 (nominal/max/min), thread length b max/min, head d k plain max / knurled max / min, head height k max/min, key s nominal/max/min, key engagement t min, g 1/g 2 max, thread blank d s1 max/min, e min, fillet r min |
| Shoulder tolerance | f9 on the ground shoulder — the running clearance for linear and rotary pivot duty |
| Family note | Metric shoulder screw; inch counterpart ASME B18.3 shoulder screws, small-size slotted variant DIN 927 |
| Materials / strength | Not tabulated by the collected specification — per RFQ (alloy steel, property class and stainless grade per drawing callout) |
| Nominal thread | P — pitch (mm) | d s nominal — f9 (mm) | d s max (mm) | d s min (mm) | b max (mm) | b min (mm) | d k plain head max (mm) | d k knurled head max (mm) | d k min (mm) | k max (mm) | k min (mm) | s nominal (mm) | s max (mm) | s min (mm) | t min (mm) | g 1 max (mm) | g 2 max (mm) | d s1 max (mm) | d s1 min (mm) | e min (mm) | r min (mm) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| M5 | 0.8 | 6.5 | 6.487 | 6.451 | 9.75 | 9.25 | 10 | 10.22 | 9.78 | 4.5 | 4.32 | 3 | 3.08 | 3.02 | 2.4 | 2.5 | 2 | 3.86 | 3.68 | 3.44 | 0.25 |
| M6 | 1 | 8 | 7.987 | 7.951 | 11.25 | 10.75 | 13 | 13.27 | 12.73 | 5.5 | 5.32 | 4 | 4.095 | 4.02 | 3.3 | 2.5 | 2.5 | 4.58 | 4.4 | 4.58 | 0.4 |
| M8 | 1.25 | 10 | 9.987 | 9.951 | 13.25 | 12.75 | 16 | 16.27 | 15.73 | 7 | 6.78 | 5 | 5.095 | 5.02 | 4.2 | 2.5 | 3.1 | 6.25 | 6.03 | 5.72 | 0.6 |
| M10 | 1.5 | 13 | 12.984 | 12.941 | 16.4 | 15.6 | 18 | 18.27 | 17.73 | 9 | 8.78 | 6 | 6.095 | 6.02 | 4.9 | 2.5 | 3.7 | 7.91 | 7.69 | 6.86 | 0.6 |
| M12 | 1.75 | 16 | 15.984 | 15.941 | 18.4 | 17.6 | 24 | 24.33 | 23.67 | 11 | 10.73 | 8 | 8.115 | 8.025 | 6.6 | 2.5 | 4.4 | 9.57 | 9.35 | 9.15 | 0.6 |
| M16 | 2 | 20 | 19.98 | 19.928 | 22.4 | 21.6 | 30 | 30.33 | 29.67 | 14 | 13.73 | 10 | 10.115 | 10.025 | 8.8 | 2.5 | 5 | 13.33 | 12.96 | 11.43 | 0.8 |
| M20 | 2.5 | 25 | 24.98 | 24.928 | 27.4 | 26.6 | 36 | 36.39 | 35.61 | 16 | 15.73 | 12 | 12.142 | 12.032 | 10 | 3 | 6.3 | 16.57 | 16.3 | 13.72 | 0.8 |
Materials
- Material, property class and finish specified per RFQ — the collected specification table covers geometry only
Ordering & documentation
Documents
Shipments are backed by Mill Test Certificate (MTC), Dimensional Report, Salt Spray Test Report on request, with full batch traceability from raw material to finished product. Quality management follows the owner-confirmed compliance list: ISO 9001:2015, RoHS, REACH. Exact document sets are confirmed on the order.
Quotation
- The fastener family (ISO 7379 Hex Socket Head Shoulder Screws) plus the standard designation from your drawing — DIN / ISO / JIS / ASTM / ANSI, or a drawing for custom parts.
- Size (diameter and length), thread type (metric or inch), property class or grade, and coating or finish.
- Quantity per size and your target delivery date.
- Destination country, and any required documents (for example a mill test certificate) so the quote includes them.
Sample & supply
Minimum order quantity is 10,000 pieces. Stock items run 3–7 days. Quantities or variants outside the standard range are confirmed at quotation.
Storage & shipping
Parts are packed for export and shipped factory-direct to buyers in Europe, Asia, the Americas and the Middle East. Store fasteners dry and protected until installation, and keep coated parts in their packaging until use; specific packing and preservation requirements can be stated on the order and confirmed at quotation.
Frequently asked questions
What does the f9 shoulder tolerance mean in practice?
It is the band that makes the screw usable as a bearing pin. In the table each d s nominal carries a max/min pair roughly 0.04–0.05 mm wide — a defined running fit, not a general-purpose bolt diameter. A part bore held a few hundredths larger lets the shoulder rotate or slide with minimal play; threads in that bore would score and gall within cycles. This is why shoulder screws are specified wherever a linkage swings: the shoulder is the pivot, the threads are only the clamp.
What should an RFQ for ISO 7379 shoulder screws state?
The designation (ISO 7379), thread size (which selects the shoulder diameter per the table), overall shoulder length — not tabulated by the collected specification, so state the required shoulder and thread lengths explicitly — plus material, hardness and finish. Head style (plain or knurled per the d k rows) and quantity per size; commercial terms follow the quotation.
What is the MOQ and lead time for these screws?
Minimum order quantity is 10,000 pieces per item. Stocked sizes ship in 3–7 days; non-stock diameters, lengths or finishes are quoted with a confirmed schedule. Common sizes in this designation are widely stocked — confirm the exact schedule against quantity and size mix at quotation.
Related knowledge
- Thread-Forming vs Thread-Cutting vs Thread-Rolling Self-Tapping Screws: What the Evidence Settles on Base Material
- Screw Family Selection by Base Material: Wood, Machine and Self-Tapping Threads, Engagement and Coating
- Hex Bolts vs Socket Head Cap Screws: What the Evidence Settles on Strength, Clearance and Cost
Request a Quote
Get factory-direct pricing from the manufacturer.
What to include in your inquiry
- ✓ Standard and property class (e.g. DIN 912, ISO 4762, class 8.8) — or a drawing for custom parts.
- ✓ Sizes, lengths and thread type (metric or inch).
- ✓ Quantity per size and your target delivery date.
- ✓ Destination country, plus any coating or finish requirement.
- ✓ Any documents you need with the shipment (e.g. mill test certificate) so the quote includes them.
- ✓ Your inquiry goes straight to the factory team by email and gets a reply within 24 hours.
- ✓ Factory-direct pricing
- ✓ Standard and custom specifications
- ✓ Factory-direct export to buyers in Europe, Asia, the Americas and the Middle East
- ✓ Full fastener family support