Edited By pgk pgk on 15/07/2018 09:40:23

Don't use ANY "speed", just tap by hand….put the brass rod(s) in the chuck or collet, put tap in good tailstock chuck, put your finger behind the (unlocked) tailstock and turn the headstock by hand using, preferably, a hand crank mounted in the lathe spindle by expanding mandrel…..allow the tap to do it's own thing and make sure you use lots of back turns to free the cuts……

An alternative method that works well with small taps is to hold the tap in a pin vice and just use both hands to GENTLY cut the thread by turning the work against the hand held tap which you can then 'feel' into the cut thread.

i have one of the micro drill adaptors & have found it very useful for 'feedback' with tiny drills. Drill with drill bits made for brass, but at that size I would take the edge of the cutting lip with a stone or diamond lap, doesn't need much, a couple of strokes would suffice otherwise you'll have a pile of broken drills. Use a loupe or other means to look at the cutting edge, as soon as you detect a shiny edge that's it dulled enough. Use the fastest speed you can & peck away at it. When I use drills for brass I keep them in a separate box ( with divider compartments for ea. size. ) for future use.
Happy drilling…

George.

I drilled many dozens of 1/32" holes for Southam in an ordinary cheap bench drill mostly in brass plate but a many in tinplate and some in steel.

OK I broke about 8 drills, but that was because I found myself drilling into partly assembled bodywork through existing holes.

Very easy to drill into solid brass at sub-millimetre sizes if you take it gently and clear the drill regularly.

Neil

I have just finished a job in PB102 bronze on my Myford and in which I needed to tap 39 (thirty nine) M1.4 holes 3/16" deep. To be honest, it is not as difficult as it sounds. The most important thing is to start by centring lightly with a No.0 centre drill and use a new, high quality HSS drill. 1.1mm dia. is good for brass over a short length but, despite what the book says, you can get away with using a 1.2mm drill instead of 1.1mm for bronze. There will not be quite as much thread but they are strong enough for purpose. I have been told that 75% thread depth is still 95% efficient, so you are not losing much strength anyway.

It is also much better to never cut dry, always use a cutting oil and "3-in-1" with added PTFE will do the job for you. I drilled at about 800 rpm, with light cuts, relieving the drill frequently and tapped by hand, relieving the tap every two turns.

I have never tapped this small a size before but did all 39 holes with the same drill and the same tap and don't think you will have any problems either.

Kind regards,

Leszek

Mr Duffer,

what are u making that needs drill's that small…….?

very interested to find out…….a clock or better yet a wristwatch…..?.

ps ….my/ur lathe clutch works a treat, thank u….

Long story cut short I'm making:

A Pendulum Clock Analyser:

That needs a pendulum clock thingy to test it:

The test clock has a standard steel bob and I'm experimenting with different materials for the rod. I started with polyester cotton thread, then 1mm carbon fibre rod, currently testing 0.5mm carbon fibre rod, and I have 0.3mm diameter carbon ready for the day I manage to drill a couple matching holes:

Another reason I may be in trouble drilling tiny holes in brass could be work hardening? It's likely that out of fear of breaking drills I'm pecking too softly, rubbing rather than cutting, and thereby toughening up the brass such that the tiny drill isn't strong enough to push through. Quite a lot of bother in my workshop is caused by poor technique.

Dave

Who is this clot? You can only drill nine 0.3mm diameter holes inside a 1.1mm circle. Thirteen would overlap.

Ho hum…

Going for less than 100% thread will reduce cutting forces on the tap.

Thanks Steve, I've ordered some!

Dave