drilling a saw blade??

[zacker01]

So I have this old power hack saw i got off craigs list, its in good shape cuts nice but you neet to use a thicker, bigger blade than a regular hand held hacksaw blade to get a good, straight cut. So looking on the net for 12" power hacksaw blades that are like 1" to 1-1/4" wide (or is that tall?) by 12" long.. they are like $20.00 and up, EACH

Anyhow, rummaging through the boxes of rusty junk tools and stuff at the local pawn shop i came across 2 1-1/4 tall x 14" blades.. if I can drill a hole in one end id be able to use them. I tried, I couldnt make a mark.. I think they may be made of Kryptonite or something from some far off galaxy, left behind during the last time some person was probed..lol seriously, how to cut / drill these things?

 

[MoonRise]

If the blades in question are a 'full-hard' blade and not a bi-metal (hard teeth welded to a 'softer' backing strip), then it would be rather difficult to drill them.

EDM, laser, waterjet, or plasma could all make a hole in hardened steel without much effort.

Or you could maybe use some cobalt drill bits, low speed and pretty high feed rate, plenty of lube/coolant, clamp the blade very well, and use a mill or pretty 'good' drill press and then try and drill the desired hole in the hard piece of steel.

At which point buying some of those ~$20 blades doesn't look all that bad after all, eh?

 

[rsanter]

drill it with a solid carbide conical or ball burr

bob

 

[lilredex]

You might try this....... Put a finishing nail, head side down in your drill press, and rotate it at top speed, on the blade where you need the hole. It will create a red hot spot (spot annealling) and allow you to drill it.

You can experiment with an old (regular) hack saw blade first.

 

[BFBOB]

You might try this....... Put a finishing nail, head side down in your drill press, and rotate it at top speed, on the blade where you need the hole. It will create a red hot spot (spot annealling) and allow you to drill it.

You can experiment with an old (regular) hack saw blade first.

What a great Idea! I'm annoyed I didn't think of it, especially because I've done it by accident more than once--annealed drill bits don't drill very well.

 

[racingtadpole]

If you have a TIG available or access to one you can use that to anneal it also.

 

[zacker01]

You might try this....... Put a finishing nail, head side down in your drill press, and rotate it at top speed, on the blade where you need the hole. It will create a red hot spot (spot annealling) and allow you to drill it.

You can experiment with an old (regular) hack saw blade first.

I am definetly trying this!! Thanks!

Someone also said I can heat up the tip where i need the hole to red hot and then i can drill it but id need to re-temper the blade.

If you have a TIG available or access to one you can use that to anneal it also.

I actually do, at my dads... if the nail trick doesnt work out i can try that.. do I just heat one spot?

Thanks!!

 

[zacker01]

If you have a TIG available or access to one you can use that to anneal it also.

If the blades in question are a 'full-hard' blade and not a bi-metal (hard teeth welded to a 'softer' backing strip), then it would be rather difficult to drill them.

EDM, laser, waterjet, or plasma could all make a hole in hardened steel without much effort.

Or you could maybe use some cobalt drill bits, low speed and pretty high feed rate, plenty of lube/coolant, clamp the blade very well, and use a mill or pretty 'good' drill press and then try and drill the desired hole in the hard piece of steel.

At which point buying some of those ~$20 blades doesn't look all that bad after all, eh?

lol... maybe. but right now i have one rigged up in the saw, (I made an extension piece to reach the hole in the blade but have to hold it on the arm of the saw with a c-clamp..lol) to see if it would work and yeah it cuts nicely. Its a full hard blade looks to be stamped from one solid piece. I just dont get why they are so expensive... the only thing i can think of is these saws are probably not in use too much now that you can get a decent bald saw cheap. but for $25.00 this is fine for me.. lol just didnt think the blades were as much as the saw...lol,lol,lol.

 

[racingtadpole]

I actually do, at my dads... if the nail trick doesnt work out i can try that.. do I just heat one spot?

Thanks!!

Last time I spot annealed something, I took the paint off, marked the hole centre, used a marker to outline the OD of the hole I wanted to make, attached the earth clamp, and held the torch steady while pushing the foot pedal. Kept pushing the pedal until the heat line spread far enough to burn the marker off. If you dont have a pedal, ramp up the current and spot it just long enough to burn the marker off.

If you have an old blade handy, try a couple of times to get it down before you have a go for real. If you havent got a spare, use the end of the blade youre going to cut off after its been drilled.

 

[larry_g]

I am definetly trying this!! Thanks!

Someone also said I can heat up the tip where i need the hole to red hot and then i can drill it but id need to re-temper the blade.

Thanks!!

If you only get a bit of heat on the end of the blade you would not have to re-temper. You usually do not use the very ends of the blade to cut in a power hack saw so temper there is not important. You really don't even need a nice hole there as the blade is always in tension. I bought a used saw once where the old guy just blew holes in the blade with a torch. Not pretty but worked just fine.

lg
no neat sig line

 

[lilredex]

An even easier solution is a punch.

http://www.harborfreight.com/air-punch-flange-tool-1110.html

http://roperwhitney.com/punching/2-45.cfm

Just tried the first option on a regular Starrett blade.

 

[zacker01]

so i tried the nail in the drill thing and after 5 minutes it still wasnt getting hot enough so i decided to try a nice sharp drill, i took the blade over to my bench and gave the center punch a couple good wacks with a 2lb mallet and the blade cracked and split into two pieses...lol what the? is this thing made of glass? lol

 

[DHS]

An even easier solution is a punch.

http://www.harborfreight.com/air-punch-flange-tool-1110.html

http://roperwhitney.com/punching/2-45.cfm

Just tried the first option on a regular Starrett blade.

Just what I was thinking too.

 

[zacker01]

but if it cracked from trying to center punch a hole in it and a drill bit doesnt even scrape the surface, wont a punch just crack it too?

 

[zacker01]

PS DHS, Love your Avatar!!! lol I want one to put on my Garage door.

 

[2mJps]

Heat the end red hot use a punch over a hole in a scrap of metal let it cool. You wont be sawing with the very end or begining.

 

[lilredex]

but if it cracked from trying to center punch a hole in it and a drill bit doesnt even scrape the surface, won't a punch just crack it too?

No......see post #11. Probably the way the mfgr does it.

Take a look at those dies, the blade is fully supported around the hole while being punched. Want a picture of my test work?

 

[zacker01]

No......see post #11. Probably the way the mfgr does it.

Take a look at those dies, the blade is fully supported around the hole while being punched. Want a picture of my test work?

maybe.. was the blade you tried it on just a normal hacksaw blade? cause i think they are made of a different steel... they flex, these dont. they are maybe 1/16" thick and like I said, it cracked when I center punched it... lol i could try heating it first...