INDUSTRISALG is your imperial emergency stock — but what will you actually find there?

INDUSTRISALG was established in 1953 and stocks close to 13,000 fastener items at any given time. The range covers everything from standard metric fasteners to special materials for offshore, oil/gas and heavy industry, including a broad selection of imperial fasteners in UNC and UNF. This blog describes specifically which imperial products we keep in stock, in which dimensions and material grades, and what characterises a qualified emergency stock for Norwegian industry.

What is the industrial problem?

Imperial fasteners are not a niche requirement on the Norwegian continental shelf. They are an operational reality for maintenance departments working with older offshore installations, American-made rotating machinery, compressor vessels and subsea wellheads. The need is often unpredictable and critical: a flange bolt fails, a compressor housing has to be opened, a valve body has to be repaired. In all these situations, the right imperial fasteners in the right dimension, thread series and material grade are a precondition for getting started on the work.

A broad imperial range in permanent stock is what distinguishes a qualified emergency stock from a general fastener supplier. INDUSTRISALG is ISO 9001:2015 certified and registered in Magnet JQS and StartBANK (ID 131384), which ensures that fasteners can be delivered with full traceability documentation as standard.

Hex bolts and stud bolts in imperial UNC and UNF

Hex bolts and stud bolts are the dominant bolt types in imperial fasteners for offshore and heavy industry. INDUSTRISALG carries hex bolts in UNC threads and UNF threads from 1/4" to 1 1/2" in both series. The bolts are supplied in strength class SAE Grade 5 and SAE Grade 8 for standard industrial applications, and stud bolts in alloy steel L7 to ASTM A153 / -A320. L7 stud bolts are one of the most frequently requested components in the maintenance of flange and valve equipment on the Norwegian continental shelf, and are held in permanent stock.

Stud bolts in low-temperature steel L7 to ASTM A320 are available for offshore structural bolted joints where low-temperature toughness is a design requirement. Super Duplex stud bolts (UNS S32760) to ASTM A1082 are available for subsea and chloride-exposed environments. These material grades are supplied with a 3.1 material certificate per batch to EN 10204 as standard.

Critical sizes in permanent stock

The table below shows a selection of the imperial sizes we hold in permanent stock, with typical applications for Norwegian offshore and heavy industry:

Stud bolts keep the thread pitch constant above 1’’, hence the thread pitch remains 8UN.

Threaded rods and cutting

INDUSTRISALG carries threaded rods in imperial UNC in the most common dimensions in electro-galvanised and SS316. Threaded rods can be cut to the required length with an in-house saw, which removes the need to order special lengths from the manufacturer. This is particularly relevant for maintenance operations where the bolt length is critical and standard lengths do not fit. Cutting is carried out on all standard imperial dimensions and delivered ready cut.

Nuts and washers for imperial fasteners

An imperial emergency stock is not complete without nuts and washers in corresponding dimensions and thread series. INDUSTRISALG carries hex nuts in UNC and UNF in strength class SAE Grade 5 and Grade 8, and in acid-resistant steel A4 (316) for corrosion-exposed environments. Plain washers and spring washers in imperial sizes are available in electro-galvanised and hot-dip galvanised finish. NORD-LOCK wedge washers are available in dimensions compatible with imperial fasteners and are the standard recommendation for vibration-critical joints, where the wedge-locking principle provides documented preload retention.

Special materials for offshore and heavy industry

INDUSTRISALG carries a broad selection of special materials under the product category Special metals and extraordinary dimensions. For imperial applications this includes American materials to ASTM standard: L7 (ASTM A320) and Super Duplex UNS S32760 (ASTM A1082). In addition, we have solid experience in sourcing high-temperature materials such as Inconel 625, Inconel 718, Hastelloy C276 and Incoloy 800H, for extreme temperature and corrosion conditions in process plants and energy infrastructure.

Which standards and compliance requirements apply?

Imperial fasteners for offshore installations on the Norwegian continental shelf are subject to NORSOK M-630 for material requirements and NORSOK M-650 for supplier certification. ASME B1.1 defines dimensions and tolerances for UNC and UNF threads. SAE J429 regulates strength classes for SAE Grades. ASTM A193 and ASTM A320 define requirements for the special materials B7 and L7. EN 10204 defines certificate types, where a 3.1 certificate is the minimum requirement for critical industrial applications.

A correct purchase order for imperial fasteners states: diameter and TPI, thread standard (UNC or UNF), strength class and ASTM/SAE designation, surface treatment and certificate type.

NORD-LOCK and vibration protection

NORD-LOCK wedge-locking washers are designed to maintain the clamping force mechanically through the wedge-locking principle, independently of friction in the thread surfaces. For imperial fasteners in offshore installations, compressor housings and rotating machinery where vibration is an operational reality, NORD-LOCK washers are the standard recommendation. INDUSTRISALG carries NORD-LOCK wedge washers in dimensions compatible with UNC and UNF in permanent stock, in delta protekt, A4 (SS316) and SMO 254.

Conclusion

INDUSTRISALG is your primary source for imperial fasteners for Norwegian offshore and heavy industry. The range covers hex bolts and stud bolts in UNC and UNF from 1/4" to 1 1/2", threaded rods with in-house cutting service, nuts, washers and NORD-LOCK wedge washers in imperial dimensions, and special materials from SAE Grade 5 to Super Duplex, Inconel and Hastelloy. Close to 13,000 items are held in stock at any given time. What is a special order elsewhere is standard with us.

Checklist: specifying imperial fasteners

• Are diameter and TPI stated, with the thread standard (UNC or UNF) explicit?
• Are the strength class and ASTM/SAE designation stated, not just the dimension?
• Is the certificate type specified (3.1 per EN 10204 for critical applications)?
• Are surface treatment / material defined for the operating environment (SAE Grade 8, B7, L7, Super Duplex)?
• Is a NORD-LOCK wedge washer included in the specification for vibration-critical joints?

Related reading

• Imperial 101: What do UNC, UNF and TPI mean — and how do you identify the threads in the field?
• Marking and traceability: what you should require from a fastener supplier

Get in touch

Send us the specification with dimension, TPI, thread standard, material grade and certificate requirements, and we will confirm stock status and the correct product for your application. Contact us at post@industrisalg.no or telephone 51 63 78 00. INDUSTRISALG supplies imperial fasteners to offshore, energy and heavy industry with full traceability documentation as standard.