Any advice for drilling ?

[Baby Grand]

Would appreciate any advice for drilling snow plow cutting edge. The Plant Manager (bless her warm heart) brought a 7' piece back from the dump for me. I don't know what kind of steel it is or if HSS drills are good enough. Been procrastinating getting Cobalt, but is this stuff going to be real tough? Thanks in advance,
Jim

 

[Duffster]

The last one I tried to drill I used a magnetic frame drill but it destroyed the cutter.

I suggest a torch.

 

[Iplayfarmer]

A cutting edge is going to be very hard. I second Duffster's suggestion for a torch. Practice a bit on some scrap steel, and I'll bet you can get pretty good at putting a nice round hole in the steel.

Now for the next question... Is a torch going to change the temper of the steel enough to worry about it?

 

[ericher69]

Very slow with cobalt bits and lots of cutting fluid should do.

How many holes and what size?

 

[Baby Grand]

Then plan involved two 3/8" holes. Burning with the torch is a very good idea - why didn't I think of that? The heat affected zone will be very local to the holes if I do it right.

I may just get a good, small set of cobalt drills and try one out at fully reduced speed and with a lot of oil. Will this stuff produce a long chip or should I expect lots of little chips? Just want to know if Ineed to lean on it or go lightly. Any recommendations on brand - this won't be a HF deal for me. Personal past experience with Ace Hanson and Vermont American has been very good, but that was a long time ago.

Alternately, I was thinking of making a little 4 foot rear blade for The Plant Manager's B5100. In that case I'll just cut to length with the torch and use the existing square holes to mount it.

Thanks for all the good advice - I know I can count on you guys.
-Jim

 

[sal64]

a hss drill is ok its 1018 crs not hard.

 

[Duffster]

Is a torch going to change the temper of the steel enough to worry about it?

No. The heat is at the center, or top depending on the type of edge, away from the working edge.

 

[sandman2234]

I would think a grader blade to be heat treated all the way across, due to abrasion wear, especially at the bolt holes, but on cheap boxblade cutting edges, it might be different. I would use a torch to untemper the location around the hole, and then drill it.
David from jax

 

[jwmorris]

A plasma torch would be what I would use, no pre heat needed for the cut.

 

[rsewill]

Second the heat, then drill. Makes for a nicer hole. The drill should push through somewhat easily and you will go through some bits. Use water to lubricate.

 

[F250DSLPWR]

Mark your hole locations and the size hole you want to drill. Now take your torch and heat that spot up red hot on both sides of the metal and let it cool slowly. You can now drill the hole with your drill bit. Heating up just the hole location to red hot will take the temper out of that spot. I have done this before with hardend steel.

 

[Doppelgangar]

Why don't you just weld the edge on the blade as that is what I usually do. Never worn out a edge that quick that it needs replacing every month or two.

Ten years is the usualy life and then the bolts got to be gassed off ant way.

It only needs to be stiched on

 

[BHD]

Depending on the width of it one could weld a mild steel edge on it to drill or Pre drill it and then weld it,

There was a shop that was "rebuilding" Noble blades, (blades about 5 foot wide that ran under the ground cutting roots in farming) by cutting off the bolt holes of the old blade and welding on a new edge,

Just using a torch to cut the holes would most likely be the easiest,

 

[Taylortractornut]

Back in College and HS metal shop here in the south first thing we learned to do is drill through cotton picker spindles. Due to there shape and temper they are good punches but are easy to break of. THey are aproximately 100 times harder than supermans skull.


http://img.groundspeak.com/user/25945_500.jpg

The way were taught to do is take a few carbide tipped masonary spade bits. Set the drill press to the highest speed. My cheap taiwan rig will topp out at 1600. You dont use coolant and the tip will get read hot annealing the metal as it drills. It works really well you may need a few bits. If it was my blae Id probably just weld it with a low hydrogen rod.

A few of my blades getthis treatment. They last unless your really tough grading gravel like a , motor grader does. I know on the scraper at work when we move a road and pick up the gravel we have to change out the 1 1/4 inch by 10 inch cutting edges every 10 hours.

 

[SPYDERLK]

Back in College and HS metal shop here in the south first thing we learned to do is drill through cotton picker spindles.
The way were taught to do is take a few carbide tipped masonary spade bits. Set the drill press to the highest speed. My cheap taiwan rig will topp out at 1600. You dont use coolant and the tip will get read hot annealing the metal as it drills. It works really well you may need a few bits. If it was my blae Id probably just weld it with a low hydrogen rod.

On masonry bits the carbide tip is brazed to the steel shank of the drill. Get em red hot the tip comes off. However, if you sharpen a masonry bit well and use it slow you can drill hard steel with it on a drill press.
larry

 

[jgrieve]

Every year at a local farm product show there is a booth selling drill bits. There is a guy drilling holes in leaf springs and hard stuff like that. Last year I plunked out a few bucks and bought a set. I love them. they are high molybeum which there info says is better than cobalt. Even have a lifetime warranty. Dakota Sales, Wyndmere ND 1800-260-9944 they are even made in USA Imagine that. Otherwise a plasma torch would be best, alot less heat. If you heat with torch to remove temper let it cool slowly before drilling.

 

[Taylortractornut]

The braze never got red hot just the very end tip of the bit. It wrecked the bit after a few inches deep drilling.

 

[wdchyd]

Mark your hole locations and the size hole you want to drill. Now take your torch and heat that spot up red hot on both sides of the metal and let it cool slowly. You can now drill the hole with your drill bit. Heating up just the hole location to red hot will take the temper out of that spot. I have done this before with hardend steel.

X 2...........:thumbsup:..........Flood it with water when drilling

 

[SandburRanch]

Would appreciate any advice for drilling snow plow cutting edge. The Plant Manager (bless her warm heart) brought a 7' piece back from the dump for me. I don't know what kind of steel it is or if HSS drills are good enough. Been procrastinating getting Cobalt, but is this stuff going to be real tough? Thanks in advance,
Jim

A quick way to determine, to some extent, what you are up against when drilling unknown metal etc. is to do a center punch test with a quality punch. If the punch curls back leaving no indentation in the material a HSS bit may have a problem. If a slight dent is made, HSS with slow speed, cutting oil and plenty of time may get results. It's a judgment call at punch time. I didn't say LUNCH time although you may need to take a lunch.:laughing:

 

[Baby Grand]

Lots of good ideas & advice - thanks, guys. I'll start of with Sandbur's punch test and if it just bounces, I'll try heating with the oxy torch and try the punch test again. If I get the same result ... then I'll worry about lunch.