ISO 4026 Flat Point Hex Socket Set Screws
ISO 4026 hex socket set screws with flat point, M1.6 to M24 — the residual-load set screw whose flat end bears against a flattened seating spot — with the full collected 13-size table: pitch, point diameter, hex socket geometry and key engagement.
Last updated: 2026-11
Specifications
The flat point is the set screw you specify when the clamped part must survive repeated adjustment: instead of digging a cup into the shaft, the flat end spreads its residual load over a flattened seating spot, so re-tightening does not deepen a scar and case-hardened or thin-walled mating parts are not punctured. ISO 4026 covers the standard metric series M1.6 to M24 with a hex socket drive — the same wrench sizes as the DIN 913 line it aligns with — and the collected table lists every size: pitch P, flat point diameter d p (max/min), minimum across-corners width e of the socket, key width s (nominal/max/min), and key engagement depth t. One reading note is reproduced from the source rather than resolved: the t values print as two rows carrying bare markers "1" and "2" with no legend on the collected page, so both rows are shown verbatim in the table below. The sibling pages of the same catalogue print the identical row structure labeled "short screw" and "long screw" (see the ISO 4027/4028/4029 tables), but for ISO 4026 itself the split is left uninterpreted. For the cup-point counterpart that maximizes holding power at the cost of a seating scar, see the ISO 4029 page on this site.
| Standard | ISO 4026 — hexagon socket set screws with flat point |
|---|---|
| Series | M1.6 – M24 (13 sizes tabulated) |
| Tabulated geometry | Per size: pitch P, point diameter d p max/min, socket across-corners e min, key width s nominal/max/min, key engagement t (two printed rows, labels "1"/"2", no published legend — reproduced verbatim) |
| Point style | Flat point — bears on a flattened spot; lowest mating-part damage of the socket set-screw points, for repeated adjustment |
| Family note | Metric counterpart of the flat-point socket set screw line (DIN 913); point-style siblings ISO 4027 cone, ISO 4028 dog, ISO 4029 cup |
| Materials / strength | Not tabulated by the collected specification — per RFQ (property class and stainless grade per drawing callout) |
| Nominal thread | P — pitch (mm) | d p max (mm) | d p min (mm) | e min (mm) | s nominal (mm) | s max (mm) | s min (mm) | t min — printed row "1" (mm) | t — printed row "2" (mm) |
|---|---|---|---|---|---|---|---|---|---|
| M1.6 | 0.35 | 0.8 | 0.55 | 0.809 | 0.7 | 0.724 | 0.71 | 0.7 | 1.5 |
| M2 | 0.4 | 1 | 0.75 | 1.011 | 0.9 | 0.913 | 0.887 | 0.8 | 1.7 |
| M2.5 | 0.45 | 1.5 | 1.25 | 1.454 | 1.3 | 1.3 | 1.275 | 1.2 | 2 |
| M3 | 0.5 | 2 | 1.75 | 1.733 | 1.5 | 1.58 | 1.52 | 1.2 | 2 |
| M4 | 0.7 | 2.5 | 2.25 | 2.303 | 2 | 2.08 | 2.02 | 1.5 | 2.5 |
| M5 | 0.8 | 3.5 | 3.2 | 2.873 | 2.5 | 2.58 | 2.52 | 2 | 3 |
| M6 | 1 | 4 | 3.7 | 3.443 | 3 | 3.08 | 3.02 | 2 | 3.5 |
| M8 | 1.25 | 5.5 | 5.2 | 4.583 | 4 | 4.095 | 4.02 | 3 | 5 |
| M10 | 1.5 | 7 | 6.64 | 5.723 | 5 | 5.14 | 5.02 | 4 | 6 |
| M12 | 1.75 | 8.5 | 8.14 | 6.863 | 6 | 6.14 | 6.02 | 4.8 | 8 |
| M16 | 2 | 12 | 11.57 | 9.149 | 8 | 8.175 | 8.025 | 6.4 | 10 |
| M20 | 2.5 | 15 | 14.57 | 11.429 | 10 | 10.175 | 10.025 | 8 | 12 |
| M24 | 3 | 18 | 17.57 | 13.716 | 12 | 12.212 | 12.032 | 10 | 15 |
| Nominal size | Thread pitch (mm) | D max — body dia (mm) | J max — flat point dia (mm) | L preferred min — flat point (mm) |
|---|---|---|---|---|
| M3 | 0.5 | 2.10 | 2.0 | 3.0 |
| M4 | 0.7 | 2.75 | 2.5 | 3.0 |
| M5 | 0.8 | 3.70 | 3.5 | 4.0 |
| M6 | 1.00 | 4.25 | 4.0 | 4.0 |
| M8 | 1.25 | 6.00 | 5.5 | 5.0 |
| M10 | 1.50 | 7.40 | 7.0 | 6.0 |
| M12 | 1.75 | 8.60 | 8.5 | 8.0 |
| M16 | 2.00 | 12.35 | 12.0 | 12.0 |
| M20 | 2.50 | 16.00 | 15.0 | 14.0 |
| M24 | 3.00 | 18.95 | 18.0 | 20.0 |
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 4026 Flat Point Hex Socket Set 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
When does a flat point beat a cup point on a set screw?
When the clamped part is harder than the screw, thinner than the cup depth, or must be re-adjusted often. A cup point (ISO 4029) digs a ring into the mating surface — maximum resistance to rotation, but the scar grows with every re-tighten and the point can pierce thin walls. A flat point spreads the load on a small flat, so it is the standard choice against hardened shafts, for spacers and collars that get repositioned, and anywhere the mating face is finished. The trade is holding power: against smooth rotating loads, specify the cup point or add a key.
What should an RFQ for ISO 4026 set screws state?
The designation (ISO 4026), thread size, length, material and property class or stainless grade, finish, and quantity per size. The socket key widths and engagement depths are in the table so the assembly workstation can pick the right hex key; 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