I'm looking to buy a 4" core drill bit. Can rent one if they have it when I need it but usually they don't. I've been looking around the web checking, looked on sleezebay and just not sure about some of that stuff and have no knowledge of good brand names with reliable quality, etc., or what to stay away from.
What will it be used for, brick, concrete for setting handrail. Seems like I've done a bunch of that lately, hate core drilling! Looking at wet bits to go on stand alone rig. What are some good names out there? Any American made? As always, thanks to all for any info.
Shawn
Shawn,
http://www.ukam.com/diamond_bits.htmHaven't used these but claims to be made in the US.
I tend to use the higher quality bits cuz I'm not very patient when it comes to core drilling. I've had pretty good luck with Core Bore bits. Er'y once in a while I get a dud though. I found out last year that using a file to dress the cutting surface on the bit helps alot.
http://www.discount-equipment.com/category/5478-diamond-products/?gclid=CMPj-Lbd4qYCFUbf4Aodb0f4zAI've bought and rented them from many different sources but most recently from United Rental. They replaced the "dud" for free and usually have a good supply in stock. Might check with several local rental stores to see who carries the most, best supply of drill bits.
Shawn,
I have gotten a couple of bits through Copperstate Bolt.
I use a Milwaukee with a vaccum base. Definitely watch your water flow. Too much is not good.
Have a Great Day, Brent
CUMMINS, Best bit I found is from Fastenal , they are a "SILVER" color not black. Before that used Diamond Products orange grade (fair) also there top of line black (also fair). The Fastenal SILVER can get 200-250 / 4" deep holes compared to the others 100-150 holes. Also for H.R. I use only 3" dia. plenty big enough for grout & some "Play"!!!!! From: Sixburgh knockin' on SEVENS door, dem' STILERS'
It's funny you should mention them, I've got a friend that works there and said if I needed anything let him know.
Hey Shawn, can't recall brand names but core drills are like anything esle-ya get what ya pay for. DON'T ever bid a concrete drill job lump sum. Always do it by the hour plus cost of bit. Brick and block cut like butter. Reinforced concrete can put you in the poor house. I did a 16" dia. by 30" thick bridge butt and it took 3 days. The concrete was made of Jamestown quarts and it had 1-1/4" rebar. Only use enough water to keep the hole clean. To much water can cause glazing of the bit and the material your cutting. Once that occurs you SOL, almost. Once the bit glazes it stops cutting. The way to fix it is back the drill out of the hole and take a grinding wheel and hold it flat against the concrete and then feed the drill into the wheel. May have to do this several times to get the diamonds exposed again. I have seen sand thrown into the curf when a grinding wheel wasn't available. If you ever have to do a large core or a really deep one be sure to get the biggest machine you can and use the Hilti anchors that are driven in with a BFH. Use the largest anchors the the machine will take. Use 2 anchors if possible. Make sure the leveling legs are tight after setting anchors. In a large diameter or deep hole machine movement will cause more heart ache than I care for. Have been on core jobs in buildings where they had the floors xrayed to be sure that no conduits or other undesirable might get in the way.
Could't answer you question about brand names but I hope the info helps. Your not the only one who doesn't like core drills- Ted
If I need an item that I don't use very often but find that I could benefit by owning it, I can usually get the rental company I do business with to give me a good deal on a used one. I especially use this trick with core drill bits and such. It's easy to tell if a bit is good or not on visual inspection.
Jon
My Grandpop had a lapidary diamond saw. When it got to cutting slowly, He would cut a regular house brick to wear away the binder and expose sharp diamond edges.
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