BS 4439 Metric Screwed Studs

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 4439 Metric Screwed Studs) 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 1,000–10,000 pieces depending on size. Stock items run 3–7 days. High-strength and custom parts run 15–25 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.

Why do the two ends of a BS 4439 stud have different thread classes, and which do I need?

Because the two ends do different jobs. The nut end works against a nut you fit and remove, so a normal medium external fit (class 6g) gives easy assembly with standard bolts-class clearance. The metal end is screwed in once and expected to stay put, so the closer 4h class — or a specified oversize — controls the stud-to-component connection more tightly: less wobble on the first seating, and a defined interference option where the housing thread is worn or where vibration wants extra grip. The tapped hole is cut to match: 4H for the closer class, 6H where the application permits the looser internal fit. On an RFQ, name the class for each end (6g nut end is the default; the metal end needs your decision), the engagement depth (1D or 1.5D are the typical purchaser-specified engagements), and the free length under the nut. The plain portion between the threaded ends, including thread run-outs, is part of the cut length — the collected page does not tabulate its ladder, so it is quoted per RFQ.

Screwed studs (BS 4439 style) or weld studs — how do I choose for a frame-up?

It is decided by whether the joint ever needs the stud unscrewed from its seat. A BS 4439-style screwed stud threads into a prepared tapped hole: the housing needs the drilling and tapping operation, but the stud is replaceable, re-positionable, and the metal-end class can be tightened (4h or oversize) against a worn bore — the right choice for machine frames, covers and any flange maintained from the nut end. A weld stud (the arc stud welding route, stud and ceramic ferrule per ISO 13918, welded per BS EN ISO 14555) needs no tapped hole at all — it is drawn-arc or tip-ignition welded through or onto the base material, giving a one-sided, leak-tight attachment fast enough for high-volume sheet and panel work, at the cost that removal means cutting. Both types are supplied in this catalog: order screwed studs by the BS 4439 dimensions here (diameter 3–39 mm, engagement and lengths per RFQ) and weld studs by their ISO 13918 designation; confirm the process side with your welding setup at quotation.