I have a set of the cheap Summit ones and have used them effectively. If you are really cheap or just in a fix then just cut a vertical slot or two in the threads of a bolt and use that, you'll get the same result. For the price of the Summit ones, it's probably cheaper just to buy them than make your own....
This^^^. For $10 the summit ones are nice to have. But if you are missing a size, a grade 8 (preferably) bolt and dremel cutoff wheel will create the exact same thing it about one minute.
as a former machinist of 42+yrs, i have done this many, many times on odd size female threads if a chaser is not available, or i needed a job completed without enough time to procure one.
a dremel is nice, but if you don't have one, a hacksaw will, and does, work.
one thing to watch, however, if you don't want to bottom tap your female holes. [yes, that is the proper nomenclature !
i can hear the jokes and comments already.] make SURE your aftermarket bolts or studs do not bottom out on the existing threads. this is especially important for using bolts. even 1/2 a thread can give you false torque readings, plus bad clamping loads.
