MGF subframe bolts

Take a file to it and it will work easily as long as a sharp tool is used. Blunt tools overheat it and then it hardens and embrittles. You will find that it will strip threads readily when overtightened where a similar higher carbon steel will snap the fastener instead.

I'm really glad that I found this "thread "

I was just checking that I have all the new bolts that I need to refit the subframe and I just noticed that they are all A2-70!

Looks like I need to order some more.

I was aware of a chap who was rebuilding a series Land Rover & making a stonkingly good job of it too. This was pre mobile phones with cameras & he was proudly showing me his picture album which he took everywhere to show anyone that showed even the slightest interest. Over a pile of spares he was buying at our local Landy supplier, he announced that he had had some special windscreen hinge bolts made for him out of stainless. He’d taken all the Whitworth & UNF hardware out & replaced them with the nearest metric equivalent. I then ruined his day, probably a lot more than a day when he told me he’d replaced EVERY bolt in the entire vehicle with stainless.
I jokingly asked if he’d used stainless on suspension, head bolts & the like. “Oh yes everything” he answered proudly. “What” was the simultaneous gasp from all present ! There was then the crumping sound of a once proud man collapsing on the floor.
They might look nice but restrict them to things that don’t take the strain; under the bonnet possibly.
Some fancy bolt heads are pretty as well but if you can’t get the same grunt on them as you can a hex head don’t entertain them if they won’t take the torque.
Avoid at all costs any hardware that might be made out of anything other than quality steel; old battleships don’t make good screws, they probably fall short as fence posts.
M

Im presuming the subframe to body bolts must have been specified between 2002 and 2003 with the old 'cutter' type bolts being replaced by conventional bolts that seemed much stronger. Thankfully it made the experience of lowering the back of the front subframe on my 2003 135 an awful lot easier than it was on the 2002 115. Cutter bolts are a fine idea in an entirely dry environment but not ideal for the underside of cars.

I always run a tap down (strictly up) a thread when on with an underside job & depending on what it does depends on whether I use copper grease, graphite grease or leave it dry.
Don’t ask what criteria I use when deciding, it’s as mysterious now as it was when I followed my dads example. Big stuff tends to get copper, small graphite & dry if I forget (!).
M