Hi Bob
This just my 2 cents
Brass is soft so to speak unlike steel one that's plated...if the bit hits the steel it's gone but if it hits the brass ,it's good chance the bit is OK..
You don't want anything like steel next to the bit, that's why you must take great care when you are switching out the bits, you don't want to kick one...and turn it into a paper weight....
One more point about brass guides, they will stay in place unlike the steel plated ones,,, the plating is like a lub job so to speak and when you have brass on brass they hold,,,,just like pipe fitting....they give just a bit and lock on...
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