BS 4190 Table 11 — ISO Metric Hexagon Head Screws, Faced Under Head Only
BS 4190-2001 table 11, ISO metric hexagon head screws faced under head only, M6 to (M68): pitch, diameter, across flats and corners, head height, fillet, washer face and chamfer ladders — the heavy-series British metric hex screw.
Last updated: 2026-11
Specifications
BS 4190 is the British heavy-series hexagon standard, and its table 11 covers the variant faced under the head only — no washer face, just a machined bearing surface — in the large metric sizes the general ISO 4014-family pages stop short of. The collected table runs M6 through (M68) in two segments (M6-(M33) and M36-(M68)): pitch P (1.0 at M6 to 3.5-class at the top end), diameter d max/min, across flats s max/min, across corners e max/min, head height k max/min, fillet radius R max/min, and the washer-face-adjacent rows dw and c marked Ref., plus runout a. This is the ladder for heavy structural and plant hex screws in the sizes and "faced under head only" finish that British practice orders as BS 4190 — heavier heads than the ISO equivalents at the same nominal size.
| Standard / scope | BS 4190-2001 table 11 — ISO metric hexagon head screws, faced under head only, M6 to (M68), non-preferred sizes parenthesized as printed |
|---|---|
| Pitch P | 1.0 (M6) to 3.5-class at (M68), per size as the P row prints |
| Width across flats s / corners e | Per-size max/min ladders across both segments as printed (e.g. s nominal 10 at M6 through the heavy ladder at the large sizes) |
| Head height k / fillet R | k max/min and R max/min rows per size |
| dw / c (Ref.) | Washer-face-adjacent bearing and chamfer rows marked Ref. — the "faced under head only" feature |
| Not tabulated | Property classes, lengths, finishes — per RFQ |
Materials
- BS 4190 hex screws serve heavy plant, structural repair and marine work where British practice still cites the standard; supply is high-tensile steel, self-colour, zinced or hot-dip galvanized. The "faced under head only" finish matters where the joint bears on the bare shank face without a separate washer — the facing gives a flat bearing seat without the raised washer face that spacers and rose joints would rock on. If the drawing says BS 4190, quote it literally; the ISO equivalents are lighter-headed and will not present the same bearing width
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 (BS 4190 Table 11 — ISO Metric Hexagon Head Screws, Faced Under Head Only) 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 would BS 4190 be ordered instead of the ISO hex screw standards?
Three cases: the drawing or the asset's maintenance manual literally cites BS 4190 (common on British-built heavy plant, dockside and waterworks equipment); the joint needs the heavier head and larger bearing dimensions at a size where the ISO ladder stops or thins out (this table runs to (M68)); or the "faced under head only" variant is wanted where a washer-face would interfere with the mating part. In each case the standard designation carries the order — the geometry here is the verification ladder, and mixing an ISO screw into a BS 4190 callout shows up as a bearing-width and head-height mismatch at fitment.
What does "faced under head only" change compared with a fully washer-faced screw?
The bearing surface. A washer-faced screw carries a raised cylindrical face that seats on its edge; the table 11 variant is simply machined flat under the head. Flat-facing seats anywhere it lands (good against rough or un-machined surfaces and where a washer would be omitted), while the washer face keeps the bearing load on a controlled diameter (good against softer materials and torque-tension repeatability). The dw and c rows marked Ref. here are the residual bearing/chamfer geometry of that flat face. Choose per the mating surface, and keep the choice consistent across a joint — the two variants seat differently under the same torque.
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