DIN 908 Hexagon Socket Screw Plugs (Cylindrical Thread)
DIN 908 screw plugs with hexagon socket and cylindrical thread, M10 to M64 with G pipe-thread variants — the flat-seated plug that seals through a washer against a machined face — with the full collected table: seat diameter, socket width, plug length and engagement depths per size.
Last updated: 2026-11
Specifications
DIN 908 is the cylindrical-thread counterpart of the DIN 906 taper plug: instead of sealing in the thread, it carries a flat bearing face — the d 2 seat diameter — that clamps a sealing washer against a machined flat around the port, while the hexagon socket in the face lets it be driven flush. That architecture trades the taper's consumable-free metal seal for serviceability: the plug can be removed and re-fitted many times without wearing a tapered interference, and the seal is renewed by replacing a washer, which is why DIN 908 dominates on pump covers, gearboxes, filters and any equipment port that is opened in service. The collected table runs M10 to M64 across block tables, and for each size tabulates: the pitch P (with fine-pitch rows on the larger sizes), the G pipe-thread designation where a pipe-thread variant shares the body size (G 1/8 A at M10 through G 2 A at M60), the chamfer c, the seat diameter d 2 with max=nominal / min limits — the washer-bearing circle that does the sealing — the e minimum across-corners, the plug length i as Nominal with max/min limits, the overall L, the hex socket width s as Nominal with max/min limits, the socket depth t minimum, the w minimum under-head wall, and the weight per 1000 units. Footnoted reference values are kept out of the rendered specification per the collected page's own "not standardized" note. Materials and finishes are not printed by the collected specification and follow the drawing callout.
| Standard | DIN 908 — hexagon socket screw plugs with cylindrical thread and sealing face |
|---|---|
| Series | M10 – M64 (metric rows), with G pipe-thread variants (G 1/8 A to G 2 A) in the same body sizes |
| Tabulated geometry | Per size: pitch P, G pipe-thread designation where tabulated, chamfer c, seat diameter d 2 (max=nominal / min), across-corners e min, plug length i (Nominal / max / min), overall L, hex socket width s (Nominal / max / min), socket depth t min, wall w min, weight per 1000 units |
| Dimensions at M10 (G 1/8 A) | P 1; d 2 max=nominal 14 / min 13.57; e min 5.7; i nominal 8 (max 8.2 / min 7.8); L 11; s nominal 5 (max 5.15 / min 5.03); t min 5; w min 3; weight 6.34 kg/1000 |
| Dimensions at M20 (G 1/2 A) | P 1.5; d 2 max=nominal 25 / min 24.48; e min 11.4; i nominal 14 (max 14.2 / min 13.8); L 18; s nominal 10 (max 10.19 / min 10.04); t min 7.5; w min 4; weight 37.5 kg/1000 |
| Dimensions at M42 (G 1 1/4 A) | P 1 / fine 2; d 2 max=nominal 49 / min 48.38; e min 25.2; i nominal 16 (max 16.2 / min 15.8); L 21; s nominal 22 (max 22.275 / min 22.065); t min 10.5; w min 4; weight 187 kg/1000 |
| Dimensions at M60 (G 2 A) | P 1 / fine 2; d 2 max=nominal 68 / min 67.26; e min 36.6; i nominal 20 (max 20.2 / min 19.8); L 25; s nominal 32 (max 32.33 / min 32.08); t min 14; w min 4; weight 445 kg/1000 |
| Materials / strength | Not tabulated by the collected specification — per RFQ (material, hardness and finish per drawing callout) |
Materials
- Material 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 (DIN 908 Hexagon Socket Screw Plugs (Cylindrical Thread)) 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 actually seals a DIN 908 plug — the thread or the seat?
The seat. The thread is cylindrical, so it clamps but does not seal; the sealing happens at the d 2 face where the plug, through a sealing washer, presses against the flat machined around the port. That is why the table gives d 2 as a proper tolerance band (max=nominal 25 / min 24.48 at M20) — it is the washer-bearing diameter, and the washer's inside diameter must match it, not the thread. In practice this is the plug's main advantage over a taper-thread plug: the seal is a replaceable consumable, so a plug opened every service interval keeps sealing indefinitely while a DIN 906 taper wears its port. The trade is the machined flat — the port face must be square and smooth, because a rough or scored face defeats the washer seat regardless of tightening torque.
Why do the G pipe-thread variants matter for ordering?
The collected table pairs several body sizes with G pipe-thread designations — G 1/8 A on the M10 body through G 2 A on the M60 body — meaning the same plug geometry is available threaded to ISO 228 parallel pipe thread instead of metric. Equipment designed on European hydraulic practice often taps ports as G threads, so the plug specified is "DIN 908, G 1/2 A" rather than "M20": identical seat diameter, length and socket, different thread form. The two are not interchangeable — a G-thread plug will not seal or seat properly in a metric-tapped port — so the port drawing decides the designation, and quoting should carry the thread form exactly as drawn.
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