Basic Info
Model NO.: ASTM A320-L7
Material: High Strength Steel
Connection: Common Bolt
Head Style: Round
The Standard: ASTM
The Grade: L7
Export Markets: USA, Canada, Brazil, UK, France, Germany, Spain, Italy, Switzerland, Dubai, Singapore, Malaysia, Japan, Korea.etc.

Additional Info
Trademark: M
Packing: in Bundles Then on 900kgs Pallet
Standard: ASTM
Origin: Ningbo, China

Product Description
1). Standard, ASTM A320-L7 threaded rod
2). Grade, Gr.L7
3). Material, Carbon, alloy, stainless, brass, etc.
4). Surface, Plain, black, ZP, ZY, H. D. G., Teflon Coated etc.
5). Packaging, In Bundles then on 900KGS Pallet


1.Scope
1.1 This specification covers alloy steel bolting materials for pressure vessels, valves, flanges, and fittings for low-temperature service. The term “bolting material” as used in this specification covers rolled, forged, or strain hardened bars, bolts, screws, studs, and stud bolts. The bars shall be hot-wrought. The material may be further processed by center less grinding or by cold drawing. Austenitic stainless steel may be solution annealed or annealed and strain-hardened.

1.2 Several grades are covered; including both ferritic and austenitic steels designated L7, B8, etc. Selection will depend on design, service conditions, mechanical properties, and low-temperature characteristics.

2. Materials and Manufacture
2.1 Heat Treatment:
2.1.1 The bolting material shall be allowed to cool to room temperature after rolling or forging. Grades L7, L7A, L7B, L7C, L7M, L43, L1, L70, L71, L72, and L73 shall be reheated to above the upper critical temperature and liquid quenched and tempered. Grades B8, B8C, B8M, B8T, B8F, B8P, B8LN, and B8MLN shall receive a carbide solution treatment. Products made from such material are described as Class 1. This shall consist of holding the material for a sufficient time at a temperature at which the chromium carbide will go into solution and then cooling in air or in a liquid medium at a rate sufficient to prevent reprecipitation of the carbide.
2.1.2 When increased mechanical properties are desired, the austenitic bolting materials shall be solution annealed and strain hardened if specified in the purchase order.
2.1.3 For L7M bolting, the final heat treatment, which may be the tempering or stress-relieving operation conducted at 1150°F [620°C] minimum, shall be done after machining or rolling of the threads.