Hex Head Bolt readily available in US with 12.9 equivalent rating or +

[ExDrill]

Hi,
We are currently searching a fastener, that is readily available in the USA in quantities of 50 maximum say, with a hex head and nut that has a 12.9 or equivalent tensile strength. I come from an Australian engineering background and am unfamiliar with the USA market. I am only familiar with 10.9 that we sometimes use on trucks. Currently we buy Unbrako brand socket head cap screws (to achieve the greater strength of 12.9) and the question came up from my boss who detests them due to their serviceability in the field requiring special allen type keys wrenches. Maybe this is a question for the aeronautical boys but then again they probably only use titanium and aluminium due to the cold temp.

Really we would prefer the UNC thread form due the availaility of 2H and equivilent nuts.
Cheers,
Exdrill

 

[MikeHalloran]

To answer a question that wasn't quite asked...

My first real job after college was as a manufacturing process engineer for Ford. Of course they bought custom machine tools for everything. They were very fussy about the fasteners; everything was put together with hex socket head bolts or screws. The reason was simple; engineers like me could carry a full set of wrenches in a labcoat pocket for when adjustments were required. We also carried cigars in our pockets for use in bartering with union tradesmen. (I have no idea what sort of currency is now required in these tobacco-free PC times to secure a forklift quickly or to make a union steward disappear).

Much later, I worked on dirt bikes. Hex socket head fasteners are sometimes sold into that market, sort of a fashion trend that comes and goes. They're a nightmare on a dirt bike because you have to spend beaucoup time picking all the dirt out of the socket before you can get the wrench in. Phillips head screws are a much better choice because you don't have to get every fleck of dirt out in order to get the driver to engage, the tapered recesses are less likely to stay full of dirt, and a little fine dirt even keeps the bit from slipping.

For larger fasteners, out in the bush, from a service perspective, despite the extra weight of a set of proper wrenches, or even a rusty dull pipe wrench, hex heads are a better choice than hex socket heads.







Mike Halloran
Pembroke Pines, FL, USA