# Drilling HSS steel



## Darley (Dec 14, 2008)

I have a friend who give me some of is broken HSS cuting blades, I do want do some tools and wondering the best way to drill the HSS, a friend at the club told me to use a masonnery drill bit, any one know another way? all help will be apreciated. Thanks


----------



## pipecrafter (Dec 14, 2008)

Masonry bits are designed to pulverise.  They're no good for metal of any kind.

If those saw blades are hardened, your best bed might be a carbide tipped drill bit.  Go slow, use plenty of coolant/lube, and have a couple spare bits on hand just in case.  You *can* drill hardened steel with HSS drill bits, but if you've never done it before, it could be frustrating.


----------



## low_48 (Dec 14, 2008)

Cobalt drill bits are what you want. They are the next general hardness up from high speed steel. Here is a reference of what you want.
http://www.toolbarn.com/category/cobalt-drill-bits/


----------



## jskeen (Dec 14, 2008)

You can try cobalt, titanium dioxide, whatever else you can find, but if those blades are REALLY hard, like as in knife blade hard, anything above about 52 rockwell C, the only thing that is actually going to put a hole in it is a solid carbide spade bit, something like the ones here:  http://www.carbidedepot.com/DynamicLanding.aspx?CategoryID=5 

Just remember, drill slow, use oil and be sure to have a piece of steel backing the one you are drilling, as these things shatter like glass if they actually punch out the back of a hole.  (most of the time)


----------



## Darley (Dec 14, 2008)

Those blade are use for cutting steel as you know, the gold one is 2.5m/m thick the other 2 are 2 m/m the black one are from Italy 'Lyndur company' don't know the gold one they all marked HSS, I want drill a 1/8 hole and screw the cuter onto a rod like a shear scraper blade in different shape, same as this one http://tinyurl.com/5dc46n


----------



## Robert Taylor (Dec 15, 2008)

IMHO you will need to soften the steel first. this can be done by heating it to cherry red and allow it to air cool. after drilling and any other work you wish to do reheat it to cherry red and then quench it in oil. if it does not seen hard enough heat it to cherry red again and quench it in water. i really think the oil should do it and the water may make it too brittle.


----------



## JeffinWIS (Dec 15, 2008)

Darley, you should be able to drill those slitting saws with a TIALN coated carbide drill bit.  Have done it a lot "at work" on a real machining center.  Just tried it at home on a drill press.  GUHRING brand 1/8" drill bit #5514-3.17 through 1/8" thick, 60 RC, M2 tool steel.  Ran dry at 1100 rpm.  Doubt you'll get more than a half dozen holes per drill though.  Drills should be available at an industrial supplier.


----------



## pipecrafter (Dec 15, 2008)

bettyt44720 said:


> IMHO you will need to soften the steel first. this can be done by heating it to cherry red and allow it to air cool. after drilling and any other work you wish to do reheat it to cherry red and then quench it in oil. if it does not seen hard enough heat it to cherry red again and quench it in water. i really think the oil should do it and the water may make it too brittle.



M2, however, is not a water-hardening steel.  The chances of it simply shattering are pretty high.  M2 is a fickle steel, requiring soak times at temp, and a specific quench cycle.  You can't treat it like a 10xx alloy.


----------



## Paul in OKC (Dec 16, 2008)

I give a vote to carbide. That is what I would use. You might get through it with something else, but...... I don't think the masonry bits come as small as 1/8". The carbide tip on them is not really set up for drilling metal, but you might make it work.


----------



## Daniel (Dec 16, 2008)

This is a completely different question along the same line. Mainly for all you experienced metal workers. What would you recommend for drilling a 1/4" blind hole (not a through hole) as much as 1.5" into drill rod. I am already looking at carbide but what flute style? drill rod will not be hardened when I drill it


----------



## Darley (Dec 16, 2008)

JeffinWIS said:


> Darley, you should be able to drill those slitting saws with a TIALN coated carbide drill bit.  Have done it a lot "at work" on a real machining center.  Just tried it at home on a drill press.  GUHRING brand 1/8" drill bit #5514-3.17 through 1/8" thick, 60 RC, M2 tool steel.  Ran dry at 1100 rpm.  Doubt you'll get more than a half dozen holes per drill though.  Drills should be available at an industrial supplier.



Jeff Thanks, do you have the GUHRING site by any chance? will have to check here if I can find some of them


----------



## Darley (Dec 16, 2008)

Paul in OKC said:


> I give a vote to carbide. That is what I would use. You might get through it with something else, but...... I don't think the masonry bits come as small as 1/8". The carbide tip on them is not really set up for drilling metal, but you might make it work.



Paul thanks for your input, my friend told me to touch sharp the massonery tip lightly to the grinding wheel to give it something to bit on the HSS, the problem I'm facing is that the  tip of the massonery bit is silver soldered ( I think ) and may heat up to much and the tip could fly out of the bit, do you think I can drill dry or with lubrican?


----------



## btboone (Dec 16, 2008)

Eek.  I'm with Paul, a very short stiff carbide drill is about your only hope.  Just prepare for it to shatter and don't get hurt.


----------



## jhs494 (Dec 16, 2008)

MSC industrial supply carries a solid carbide straight flute spade drill. I have always referred to them as a spot drill, there is no actual flutes just a flat ground on each side. I have had some success drilling thinner tough material with these. 
Good Luck.  Be sure and wear safety glasses!


----------



## fritz64 (Dec 16, 2008)

find some body with a plasma torch, cutter they can punch a hole in your hss with very little heat.   bob


----------



## JeffinWIS (Dec 16, 2008)

Daniel said:


> This is a completely different question along the same line. Mainly for all you experienced metal workers. What would you recommend for drilling a 1/4" blind hole (not a through hole) as much as 1.5" into drill rod. I am already looking at carbide but what flute style? drill rod will not be hardened when I drill it



A good quality HSS twist drill will do fine.  Start "pecking" after getting about 3/4" deep.  Running dry try about 500 rpm.  Blue chips are not good


----------



## JeffinWIS (Dec 16, 2008)

Darley said:


> Jeff Thanks, do you have the GUHRING site by any chance? will have to check here if I can find some of them



http://www.guhring.com/drills.shtml  You'll need to download the carbide drill PDF catalog.


----------



## JeffinWIS (Dec 16, 2008)

Darly, if you have the masonry bit and a diamond wheel to sharpen it, give it a try.

Can't remember who makes them, but there are carbide bits made for drilling out broken taps.  The ones we use, the section where the flutes would be is a somewhat square cross section, with a reverse taper...bigger at the tip.  Opposing flats form the point.  There are no positive cutting edges...pressure and friction will "melt" the metal being drilled.  These work on occasion...require a LOT of down pressure.

A slower method would be copper tubing used as a drill with coarse lapping compound.  It may take 1/2 hour to do one hole, but it is cheap, safe, and almost guaranteed.


----------



## KenV (Dec 16, 2008)

Daniel -- Drill rod will cut with a good quality drill bit that is well sharpened.  It will work harden if you are not using a spiffy sharp bit.  Use cutting oil or similar and an even feed.


----------



## Paul in OKC (Dec 17, 2008)

Daniel said:


> This is a completely different question along the same line. Mainly for all you experienced metal workers. What would you recommend for drilling a 1/4" blind hole (not a through hole) as much as 1.5" into drill rod. I am already looking at carbide but what flute style? drill rod will not be hardened when I drill it



You can use a good HSS drill bit for that, just keep some coolant of some sort on it.


----------



## Paul in OKC (Dec 17, 2008)

Darley said:


> Paul thanks for your input, my friend told me to touch sharp the massonery tip lightly to the grinding wheel to give it something to bit on the HSS, the problem I'm facing is that the  tip of the massonery bit is silver soldered ( I think ) and may heat up to much and the tip could fly out of the bit, do you think I can drill dry or with lubrican?


Not likely to get it that hot, you would surely decide it wasn't working by then!


----------



## Daniel (Dec 17, 2008)

Thanks fellas, I have my DD right next to the lathe so I will just pick up a couple good quality HSS bits, already have cutting oil.


----------

