Drilling Stainless Steel

[Michael GilliganParticipant @michaelgilligan61133]

Posted by samuel heywood on 04/03/2023 00:29:14:

[…]

I was only trying to be helpful Michael, if i wasn't~ feel free to ignore my comment. My friends often do.

Yes it's a bit cheeky calling drills pilot or bullet point when they are not.

I can attempt to take a close up of the 4mm point if that's in any way helpful??

.

That would be interesting, thanks Samuel

RUWAG’s reply states that the transition is at 5mm, but you may well be right.

MichaelG.

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https://ruwag.co.uk/collections/metal-hss-drill-bits/products/turbo-metal-drill-bit#shopify-product-reviews

Edited By Michael Gilligan on 04/03/2023 07:51:49

[HopperParticipant @hopper]

The smaller drills all have the pilot point — they just don't have the larger diameter part that the bigger drills have, as it is not needed.

Edited By Hopper on 04/03/2023 08:24:59

[Paul RhodesParticipant @paulrhodes20292]

Good one Hopper!

[Michael GilliganParticipant @michaelgilligan61133]

It’s not much of a test, but …. I am pleased to report that the 3mm drill has just made very easy work of drilling-out the damaged hexagon socket in an M4 countersunk screw.

MichaelG.

[samuel heywoodParticipant @samuelheywood23031]

[samuel heywoodParticipant @samuelheywood23031]

…. hope that's of some use Michael.

On reverse of B& D's packaging it states "Bits below 3mm do not have the unique bullet pilot point but do have a specially ground point"

Looking @ my 3mm example,it just looks like a standard split point.

Maybe they decided it wasn't economic to do in small sizes at some point in the production run?

[Michael GilliganParticipant @michaelgilligan61133]

Thanks for that, Samuel

Hadn’t realised that we were talking about different suppliers

… My own comments were specific to RUWAG

MichaelG.

[samuel heywoodParticipant @samuelheywood23031]

Posted by Michael Gilligan on 04/03/2023 15:07:02:

Thanks for that, Samuel

Hadn’t realised that we were talking about different suppliers

… My own comments were specific to RUWAG

MichaelG.

I'd wager a pint of finest Ale they come from the same factory though.

Just had a look at the RUWAG uk website, if you zoom the pic~ stamped hss Germany.

I also see a flatted shank pictured , if that's relevant to anyone. The B& D ones i have are all round shank.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by samuel heywood on 04/03/2023 16:26:23:
.

I'd wager a pint of finest Ale they come from the same factory though.

[…]

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That would be a little odd, given that RUWAG explicitly stated the transition to be at 5mm drill size.

… But perhaps they are wrong [they’ve been wrong before]

MichaelG.

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Edit: __ I am very impressed to see that the website has already been updated in line with RUWAG’s respose to my review.

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Edited By Michael Gilligan on 04/03/2023 17:27:50

[Michael GilliganParticipant @michaelgilligan61133]

I don’t often post about things I have made, or done, but I am rather pleased with this:

.

.

Why? you might ask … it’s just a commercial M4 countersunk screw !

.

The thing is … it is the screw that I mentioned earlier: One of six securing a heavy lid to an even heavier box

[the details are irrelevant]

They had all been excessively tightened by some previous user [a 2.5mm Allen key needs to be a good one if you want to get-away with this] and the hexagon socket in this one was very badly damaged.

I managed to loosen the other five, but this one was particularly bad.

I shall never know whether it was down to Luck, Skill, or the quality of the RUWAG drill, but:

I drilled the hex-socket out to 3mm, to a suitable depth, to weaken the screw and let the tension relieve.

.

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Then I loosened the other five screws and shifted the lid slightly, with gentle blows from my ‘dead’ hammer … Being a countersunk screw, this stretched it a little further.

I was then able to unscrew it without difficulty.

The head didn’t detach from the screw … because the drilling was nicely concentric with the thread, and just the right size … It’s exactly what I was trying to do, and it worked: But was I just lucky ?

MichaelG.

 

 

 

Edited By Michael Gilligan on 04/03/2023 20:04:18

[Bill PhinnParticipant @billphinn90025]

Posted by Michael Gilligan on 04/03/2023 20:02:33:

I was then able to unscrew it without difficulty.

Edited By Michael Gilligan on 04/03/2023 20:04:18

What did you unscrew it with now that it was a round hole rather than a 2.5mm hex socket?

I don't know whether you were lucky, but the relatively small size of the fastener may have been on your side in responding to wallops from the hammer more obligingly than bigger fasteners might.

It doesn't look rusty either, unlike the M10x1.25 lawnmower blade bolts I had to remove recently, which needed the highest setting [reputedly "1625Nm of breakaway torque"] from a Dewalt DCF899HN-XJ 18V impact wrench to come undone.

[Michael GilliganParticipant @michaelgilligan61133]

It wasn’t at all rusty, Bill … It had just been done-up way too tight.

To unscrew it, I removed the other five screws and ‘unwound’ the top plate … there was just sufficient drag on the countersink surface to carry the screw along with it … then, with it now loose, I simply unwound the screw with my fingertip.

The thing was originally very well made, and the screw threads behave as they should … it’s just had a hard life.

MichaelG.

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P.S. __ there were no wallops involved … just gentle taps with a suitable hammer, to shift the plate laterally by about a millimetre, and thereby stretch the weakened section a little. [if doing the geometry, remember there is a clearance hole]

P.P.S.__ I have just enlarged my photo, and can see the stretched thread.

Edited By Michael Gilligan on 04/03/2023 22:43:15

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