I don't know about other branches, but with the Air Force we bought whatever brand of tools. I was in charge of a tool room for about 3 years so I have an idea on how it all worked.
No one gave 2 shits what brand the tool was, just that we had the tools required and they would work correctly.
Reason that Snap On, Matco, etc is popular is because..
A. They have GSA contracts
B. Cost (50-60% off list)
C. Marketing/Sales. They pimp their **** just like they do to the auto techs.
Also spent a long time with tool control and tool stores as my secondary duty.
As soon as the powers that be realised I actually had a passion for it instead of it just being a sh*tty second duty to aid promotion I ended up with the whole of camp's tool stores under my duristiction.
I had actually managed to provide such a good service, removed all the crappy old shelving, brought in all new stuff, laid out all the new foam drawers with dayglo shadows, provided complete sets of tools from the likes of britool and snap-on.
We went with snap-on because they were happy to etch the tooling for us, without affecting warranty, replace broken items and do us a great deal off list price. On top of that, when we did the math over a 5 year period of replacing broken/worn tools, we actually saved somewhere in the region of £100k
As such this did infact get me my promotion, but also got me a nice financial bonus for helping them save so much money in the long run. Most officers that would have typically done this job would have come in, blown the budget for their 2 year post and left a complete mess for the next guy to tidy up with no regard as to how it went on the shop floor.
Spending other peoples money was great, but every guy in our hangar finally found a new respect for tool stores - it was modern, fantastic tooling, broken items were replaced immediately from small stock holding on camp and if there was something we didnt have, they knew for a fact I would get it for them and give it a gucci home in the stores.
A lot of pride went into that job. I miss it.



