The most important step of making bolts is always the threads, at Big Bolt Nut we emphasise greatly on providing our customers the perfect threads which are again controlled in our QC process by Go and NOGO Gauges.

Please see below the details of the CNC machines which are available in our factory.

Machine Details



Year of Make

Bolt diameter

Number of Machines

Thread rolling 50 T

50 T



M-20 to M-150


Thread rolling 36 T

36 T



M-12 to M-48


Thread rolling 15 T

15 T



M-6 to M-33


Ever since we started manufacturing bolts we have always used thread rolling technology to make threads on our bolts and sockets, thread rolling is a better and much more effective way of performing threads on a bolt as compared to thread cutting, the advantage of thread rolling over thread cutting are tremendous, with thread rolling you get perfect fibre lines and unbroken fibres on the steel and when thread rolling is done after heat treatment they provide much more stronger threads as compared to thread rolling done before heat treatment.

When perfect pitch diameter is maintained on the bolts surface with the help of CNC machining and center less grinding, consistent threads with perfect GO and NOGO fitment are assured repeatedly. As a quality assurance plan we offer our customers with 100% checks for GO and NOGO during manufacturing process which is monitored by our QC and also in final inspection just before packaging.

Big Bolt Nut does 100% thread rolling on all our carbon steel, alloy steel and stainless steel hex bolts, hex screws and nuts. We are also one of the few companies in India which can do thread rolling on bolts after heat treatment, the advantage of doing thread rolling after heat treatment is that it improves the fatigue strength of the bolt and gives a longer life and performance of the bolt. We are at the present having in our factory 3 thread rolling machines of different capacity to do thread rolling on bolts up to 125 mm diameter. We also do thread rolling on all foundation bolts and anchor bolts manufactured by us.