Drilling tricks for work hardening

[Blue-Fox]

My pa bought this machine anbout 2014, for a contract needed ann AWD grader, and it’s had a gob of issues keeping the cutting edge bolts tight. They are 5/8 bolts and there’s every other hole drilled. So I got it in the shop and started poking holes. I got a box full of bits and even some that I have sharpened myself for hard steel. (Down to about a 110° point. The first 3-4 holes went well and now I think I have run into work hardening ? Can’t penetrate it with a common bit, or a 110° to just make a pilot hole. I tried putting torch to it - but I poured water on it and I’m thinking that was wrong now.

 

[Coaldust]

Try an annular cutter. For sh$ts and giggles.

 

[Blue-Fox]

Try an annular cutter. For sh$ts and giggles.

Yeah for sure, I been looking at them. Just not convinced it’s worth the money and hear of people breaking them all the time ?? Still got to drill a pilot hole right?

 

[Welder Dave]

No, just need a center punch mark or a slight divot from a small drill bit. Annular cutters use a centering pin. If you're drilling through a guide hole you wouldn't need the centering pin. I've never heard of them breaking. I'd try heating it orange hot and just let cool on it's own first. Then a drill bit might work with a good cutting fluid. Heating and quenching would typically make the steel harder.

 

[Jonas302]

Find your annular cutter on ebay or amazon if you have time to wait carbide even better ohh they will break but not all that often usually when things start to move around if you have never used them you will fall in love Also will need a weldon shank chuck for your drill

These solid carbide drill work great to keep around but are brittle again I get them on ebay https://www.mcmaster.com/products/solid-carbide-drills/carbide-drill-bits-for-hardened-steel/

Cheap thing to try is carbide masonry bits

You will never get enough heat into that mass of steel let it slowly cool for annealing and yes putting water on it was even worse

 

[willie59]

I second Jonas302, carbide tipped annular cutter. I was boring some holes in cast steel, which is a bugger to work with from the get go, using standard annular cutter with plenty of cutting fluid then suddenly it made a sound and quit cutting. Tried using new cutter, same thing. Tried cobalt cutter, nope, wouldn't move even a fraction. Steel had hardened at that spot and nothing was going through. Last resort, purchased a carbide cutter, damn thing went through it like it was butter. I'm convinced.

 

[Tyler d4c]

They will only break with improper use. Atleast from my experience

 

[Jonas302]

Pretty much every time I touch a drill bit its used improperly including what the op is doing after all its heavy equipment repair not manufacturing bits are quite expendable when you look at the overall value of repairs done

 

[Tyler d4c]

Pretty much every time I touch a drill bit its used improperly including what the op is doing after all its heavy equipment repair not manufacturing bits are quite expendable when you look at the overall value of repairs done

Yep it doesn't matter what it takes if you need a hole

 

[OzDozer]

I bought a cheap 36mm (1.4") annular cutter and a cheap Chinese magnetic drill and had no problem easily poking 8 holes in 50mm (approx 2") high tensile plate. This plate equates to about T1 tensile strength.
Take it slow and use plenty of coolant. The cheap Chinese drill even came with its own coolant bottle and feed hose into the centre of the drill.

 

[Blue-Fox]

I bought a cheap 36mm (1.4") annular cutter and a cheap Chinese magnetic drill and had no problem easily poking 8 holes in 50mm (approx 2") high tensile plate. This plate equates to about T1 tensile strength.
Take it slow and use plenty of coolant. The cheap Chinese drill even came with its own coolant bottle and feed hose into the centre of the drill.

Ive seen all that Vevor stuff and just assumed its junk. I will look into that, its not like I need it to build skyscrapers just to fix my old yellow stuff. Thanks

 

[Blue-Fox]

Pretty much every time I touch a drill bit its used improperly including what the op is doing after all its heavy equipment repair not manufacturing bits are quite expendable when you look at the overall value of repairs done

Yeah Roger that! I think we all try to stay between the ditches but damn its a drill bit!

 

[Blue-Fox]

Find your annular cutter on ebay or amazon if you have time to wait carbide even better ohh they will break but not all that often usually when things start to move around if you have never used them you will fall in love Also will need a weldon shank chuck for your drill

These solid carbide drill work great to keep around but are brittle again I get them on ebay https://www.mcmaster.com/products/solid-carbide-drills/carbide-drill-bits-for-hardened-steel/

Cheap thing to try is carbide masonry bits

You will never get enough heat into that mass of steel let it slowly cool for annealing and yes putting water on it was even worse

I’ll have a look at those options thanks a bunch

 

[Blue-Fox]

I haven’t tried putting a foot pedal on the motor yet to change speed but was a thought.

 

[OzDozer]

I forgot to add I acquired the annular cutter off eBay, but it's Chinese-made, anyway.

 

[Blue-Fox]

Sooooo there’s a couple drills floating around for sale within a reasonable distance - would you guys buy a FEIN slugger that’s drilled two holes for $750
Or a Hougen that’s been used a little bit for $500 ?? Any issues with either of them?

 

[crane operator]

I have a old hougen. Its single speed, fixed base, and a drilling SOB. Well used when I bought it. I have broken annular cutters. I have abused tools in the past and probably will continue to do so in the future.

From everything I've read, the FEIN stuff is pretty nice german built equipment. That hougen with a swivel base is a pretty hot rod tool also. Both are priced right for used, especially if either comes with some bits. I think the last cutters I bought were around $100 each.

 

[Tyler d4c]

We have a old one with variable speed and turque a newer evolution and a fein short slugger also a milwaukee battery one. Out of the bunch the battery one is ok but I really like the short slug if all I need is to drill a hole with a cutter. If a hole saw is the tool you need the speed control. The battery is 2 speed works ok with smaller drill bits I haven't tried it with a hole saw yet

 

[.RC.]

I bought a second hand fein. German made. Great quality as you would expect.

For hard stuff, I have used cheap two flute masonary hammer bits that I sharpened on a diamond wheel.

 

[digger doug]

Grader blade is not Like t-1 or any other Hi-tensile IMHO.
it's work hardening manganese rich steel.
It doesn't even oxy torch cut very well.