Mud-club

Chat & Social => The Bar - General Chat => Topic started by: andrew2986 on May 29, 2008, 09:14:58

Title: Drilling stainless ??
Post by: andrew2986 on May 29, 2008, 09:14:58: I want to modify the stainless cb arial mount, can any one let me know what type of drill bit I should use? standard HSS bits just go blunt

Cheers

Andy
Title: Re: Drilling stainless ??
Post by: wormster on May 29, 2008, 10:51:40: As I recall from my engineering days (many moons ago) stainless is a pig to machiene,

you need a hard bit ground to the right angle run the tool slowly with LOTS of lubrication.
Title: Re: Drilling stainless ??
Post by: Sharpshooter on May 29, 2008, 11:14:45: Correct wormster. It might pay you to go up in stages too. :)
Title: Re: Drilling stainless ??
Post by: wormster on May 29, 2008, 13:37:07: Quote from: Sharpshooter on May 29, 2008, 11:14:45
Correct wormster. It might pay you to go up in stages too. :)

Ahh yes that as well.
Title: Re: Drilling stainless ??
Post by: andrew2986 on May 29, 2008, 16:48:46: cheers guys, is there anything harder than a HSS drill bit?
Title: Re: Drilling stainless ??
Post by: Tommo on May 29, 2008, 19:03:02: mmm, carbide but you are talking big bucks.

it should drill fine if it isnt too bigger hole, its not that bad. just blunts your drill quicker but for gods sake dont let the stainless get very hot, thats when the problems occur.
Title: Re: Drilling stainless ??
Post by: piggysteve on May 29, 2008, 19:13:26: Andy, normal hss drill bit, plenty of lubrication but pulse the trigger of your drill.

Steve
Title: Re: Drilling stainless ??
Post by: andrew2986 on May 29, 2008, 19:50:25: thanks guys, will give it another go over the weekend

Andy
Title: Re: Drilling stainless ??
Post by: marjan on May 29, 2008, 20:15:00: Quote from: piggysteve on May 29, 2008, 19:13:26
Andy, normal hss drill bit, plenty of lubrication but pulse the trigger of your drill.

Steve

Yep that's the way I do it and keep dipping the drill bit in oil.
Title: Re: Drilling stainless ??
Post by: lee celtic on May 29, 2008, 21:12:14: Don't go up in sizes this will heat the steel around the first hole making it super hard for the second drill [-X

If you don't want to shell out for an expensive drill bit there is a cheat I have used a few times and it does work...But don't tell anyone as I work in an engineering company and if they find out they'll laugh at me..... :-$

Get an old masonry bit and grind it to the same angles as a steel hss bit (think its 118 degrees) drill at med speed with coolant of any kind and go straight through in one go or the steel will harden again.. trust me it works :D

also good for drilling out bleed nipples in calipers (or so I've heard ;))
Title: Re: Drilling stainless ??
Post by: diggerdog36 on May 29, 2008, 21:15:22: Quote from: andrew2986 on May 29, 2008, 16:48:46
cheers guys, is there anything harder than a HSS drill bit?
Cobalt, but they can shatter violently if drilled fast, what size are you wanting to drill???
Title: Re: Drilling stainless ??
Post by: andrew2986 on May 29, 2008, 21:42:28: Ive got a gutter mount I wont to convert to permanent body mount, so need to drill two holes to get a pair of M8 bolts through.
Title: Re: Drilling stainless ??
Post by: wizard on May 29, 2008, 23:28:49: The secret to drilling or machining stainless steel is.......................

Very low speed and lubrication. For a small bit of plate dont bother with lub oil or coolant just a very slow speed drill will be fine.
thicker plate requires a bit of coolant but still take it slow.

wizard