Products · Bolts
Square head bolts
Square head bolts, with or without a collar, made to DIN, BS, NFE and ASME standards or your drawing, in alloy steels, stainless, duplex and superalloys.
DIN 478
Plus BS, NFE and ASME standards
1 to 500
Single prototypes to batches of several hundred
UK, EU, US
Mill origin of every bar we use
3.1 / 3.2
EN 10204 certificates with full traceability
About Square head bolts
A traditional head, still specified
Square head bolts have a four-sided head, often with a collar underneath. The square gives a large spanner flat and sits against a shoulder or in a slot to resist turning, so square head bolts are still specified for heavy plant, rail, machine tools and the replacement of parts on older equipment. HAGUE FASTENERS makes them in the UK.
Special square head bolts are part of our regular work. Many are in duplex, super duplex or superalloys, in BSW, BSF, UNC and UNF as well as metric threads.
Typical specials
- Collared square heads to DIN 478
- Square heads for slots and jacking duties
- Heritage and replacement parts in imperial threads
- Special materials and lengths
- Copies made from a worn sample
Options
Typical specifications
Typical options. We make to the standard or drawing you specify.
| Option | What we make |
|---|---|
| Head | Square, square with collar, or special |
| Thread | Metric coarse and fine, UNC, UNF, UN, BSW, BSF and special forms, cut or rolled |
| Strength | Classes 8.8, 10.9, 12.9 and 14.9; ASTM A193 B7, B16, B8 and B8M; A320 L7 |
| Standards | DIN 478, NFE 25116, NFE 25117, NFE 25118, BS 451, BS 2708, ANSI B18.2.1 |
| Finishes | Self colour, zinc, zinc nickel, zinc flake (Geomet, Delta Protekt), hot dip galvanising, electroless nickel, PTFE fluoropolymer, phosphate or passivation |
| Documentation | Certificate of conformity, EN 10204 3.1 or 3.2, test reports, dimensional reports and FAIR |
Materials
Materials we use
Certified bar from UK, EU and US mills. See all fastener materials.
- Carbon and alloy steels: EN8, EN16, EN19, EN24, EN26, 42CrMo4, B7, B16 and L7
- Stainless steels: A2, A4, 316, B8, B8M and 17-4PH
- Duplex and super duplex: S31803, S32750, S32760 and Zeron 100
- Inconel: 600, 625 and 718
- Monel: 400 and K500
- Hastelloy: C276 and C22
- Titanium: titanium alloys
- Bronzes and non-ferrous alloys: aluminium bronze, phosphor bronze and brass
Manufacture and quality
Made in Willenhall, certified to release
Machined and threaded in our own Willenhall facility from certified UK, EU and US bar, with special processes managed by us through audited partners.
- Heat numbers traced from mill to release
- Heat treatment, NDT and coating by approved partners
- UKAS-accredited testing where specified
Related products
Related types
Questions
Frequently asked questions
Where are square head bolts used?
Square head bolts are used in heavy plant, rail, machine tools and older equipment, where a large spanner flat or a head that resists turning in a slot is needed.
What is DIN 478?
DIN 478 is the German standard for square head bolts with a collar. We make to DIN 478 and to BS, NFE and ASME standards, or to your drawing.
Can you copy an old square head bolt?
Yes. Send a photograph beside a rule for a quick estimate, then the sample. We can match the thread and head, and upgrade the material if needed.
Do you make square head bolts in stainless steel?
Yes. We make square head bolts in stainless steels, duplex and superalloys as well as carbon and alloy steels.
Square head bolt enquiry?
Send us the drawing or the standard
Send the drawing, standard or sample, with the material and quantity, and we will quote quickly.