Drilling Spring Steel

- Dremel 3.4mm grinding stone for pilot dimple

- Masonry bit with clearance/rake ground on the end, slow speed & plenty of tapping fluid.

Story:

So I bought some 1mm thick spring steel strips to make some leaf springs from. I assumed drilling a hole in them would be similar to stainless steel - I was wrong!!!

After finding a centre punch has no affect on this material whatsoever, blunting and breaking a few drill bits and other tools I dare not mention, and even playing about with annealing the stuff in the desired area I hit the internet and collected information from various sources and tried the following:

As the centre punch had no affect, I created the pilot dimple using a Dremel with the 3.4mm grinding stone at an angle - need a good eye and a steady hand but fairly easy.

Drill bit - I read that carbide tools should be used but I reeled at the price especialy considereing what I had managed to do to my exiting tools. So I got my cheap masonry bits (local DIY store style) ground some rear clearance/rake for the swarf, being careful not to touch the cutting edge. Cut at a slowish speed with plenty of drilling/tapping fluid - job's a good'n!

As I went through quite a bit of frustration to get there I though I would share.

If you already have carbide drill bits then good for you!

Edited By Thomas Gude on 01/03/2015 13:46:41

As soon as you said spring steel my ears pricked up knowing some of it's properties.

Another similar steel is that used for strapping heavy pallet loads.

However where there's a wheel there's a weigh as the Scots say and well done for sharing.

Edited By Jesse Hancock 1 on 01/03/2015 14:26:39

In extremis you can use a bit of copper tube and grinding paste, same idea as glass drilling.

Edited By Gordon W on 01/03/2015 14:32:07

Hi, if you plunge and buy some carbide drills, make sure that you have everything ridgid as they chip easilly if allowed to vibrate.

Using a masonry drill is fine provided that you can get the centre of the helix to bite and cut, rather than rub.

Bri

You can get Multi Construction TCT drill bits that have the tip diamond ground and they will drill in a number of materials from aluminium to concrete. Not tried them in spring steel but may be worth a try.

Bob

You mean to say I missed out on all that fun last week when I needed a couple of 4BA clearance holes in some spring steel strip and I just had to make do with punching their position and drilling with a normal 3.5mm HSS bit

Amazing what a bit of heat can do before you drill and again afterwards

Were you starting with annealed spring strip first to be followed by hardening and tempering after the hole drilling?

Used to work with spring steel all the time for 11 years, some with 10BA tapped holes 3/8" deep, final article to microns polished.

We just used decent hss drill bits. If I don't cut don't force, it only gets worse. Same with tapping.

I have drilled broken easy outs ( I didn't break it was a job brought into my workshop somebody trying to get broken stud out of a seagull outboard motor), oil holes in large spherical roller bearings and a new band brake band for my old heavy weight Chinese lathe the material was 32 mmx2mm steel strapping like another contributor mentioned, it has worked well so far.

I have found on some hard/tough materials  either  cut or not cut do not rub it tends to work harden the surface in some jobs I have had to turn the job over and drill from the other side ,alright if you are drilling through.

Edited By Danny Hegh on 27/06/2015 23:19:39

Good quality HSS drills slow speed and a cutting lubricant will do the job.

We used to drill hardened punch plates using sharpened masonry bits, we found lots of pressure and slow speed gave us the longest life and best cut, but we never used lubricant as this led to skidding which work hardened the surface.

Steve

Could it not be sparked?

Just a though.

Guess what I want for Christmas.

Make hole with electro erosion.

In the past I have bought solid carbide drills at reasonable cost from Anchor Drills and Tools in Sheffield on 0114 256 0700. I have no connection with the company.

Browsing through an old ME (I'm back in the early 1970's currently) yesterday at Coffee Break - and there was a letter from someone who suggested a "simple" way to drill new holes in broken hacksaw blades.

He took the carbon rod out of a battery (remember the type?) made it pointy in a pencil sharpener and then connected one end of it to a fully charged 12V battery - with the hacksaw blade forming the return path. Apparently (if you are extremely brave - and perhaps not a little foolhardy) you can poke a hole through a hacksaw blade quite easily with the carbon arc so formed!

Before the Editor has a Health & Safety fit - I should quickly add that any carbon arc is potentially very dangerous (to the eyes, hands/skin and clothing) - so drilling is much the preferred option - but (with the right precautions) a carbon arc brazing set (which I already have) might be useful for locally 'spot' annealing some hardened parts? I think I've mentioned before that this was a gunsmithing technique at one time.

IanT

Edited By IanT on 29/06/2015 21:22:18