Bolt grades are closely related to tensile strengths. In layman’s terms, the tensile strength of a bolt refers to the maximum stress the bolt can withstand before breaking. Thus, the higher the tensile strength, the higher the weight a bolt can sustain and the higher its capacity to bear impact.
High tensile bolts are used for high-stress fastening applications. For example, you would usually require high tensile bolts in the realms of construction or other similar industrial environments. These high tensile bolts help to secure heavy objects together and shoulder their weight for many years, or even decades.
Roll-fast is the biggest manufacturer for larger diameter high tensile bolts & nuts in India, we have a monthly production of over 300 tons in bigger sizes from M-16 to M-100 in 8.8, 10.9 and 12.9 grade. These bolts & nuts are used in energy sector like wind, solar, thermal and hydro energy. These are also used widely in all other kind of sectors namely, transportation, railways, heavy engineering, Valves and pump Industry, Bridges and road constructions, cross country pipelines, flange joints and other critical applications. We are the pioneers in manufacturing critical bolts & nuts for the wind energy sector in India. These bolts & nuts are manufactured only by hot forging process, and we have the complete list of machines in our factory to manufacture these bolts & nuts.
We offer High tensile bolts & nuts in 8.8, 10.9 & 12.9 grade, the choice of the grade depends upon the application and requirement of the customer. The grades 8.8, 10.9 & 12.9 have separate mechanical characteristics which are defined in the ISO 898-1. When it comes to high tensile bolts, there are Three main grades, although there are some specialist grades designed for specific applications.
- ASTM F3125
- ASTM F1554
- ASTM A354
- ASTM A449
- ASTM A307
- ISO 4014
- ISO 4017
- DIN 931
- DIN 933
- IS 1367
- BS 3692
- ASME B18.2.1
- ASME B18.2.6M
- High Tensile Strength
- High Holding capacity of heavy loads
- Pre-tension and transmit external forces by friction
HDG, Zinc Plated, Zinc Flake, Black Oxide, Xylan, PTFE, Geomat, Chrome finish
We can offer surface finishing as per customer requirement in hot dip galvanising, we take special care to ensure there is no hydrogen embrittlement in 10.9 grade with our special curing system which ensures that 10.9 grade bolts are not damaged by hydrogen embrittlement post galvanizing process. We also do zinc electroplated in blue, yellow or black color as per customer requirements.