Countersinks - what to look for

[sim]

I'm looking for some 90 degree and 82 degree countersinks to add to my tool collection. Mainly will be countersinking 3mm screw holes in aluminium RC car parts, but occasionally will use them on free machining steel.

What kind of countersinks should I be looking for. I seem to see a whole variety on ebay and some of them are really cheap. Also, they need to fit a collet or will a drill chuck do?

Thanks in advance.

[BENDER]

I'm not sure about brands off the top of my head. But, I personally prefer the single flute c-sinks, they pull a nice smooth chip in most soft metals. Multi-flute c-sinks can have a tendency to chatter, unless you have the ability to run at really slow RPM's. Either one will work in a drill chuck just fine.

[C*H*U*D]

Originally Posted by BENDER

I'm not sure about brands off the top of my head. But, I personally prefer the single flute c-sinks, they pull a nice smooth chip in most soft metals. Multi-flute c-sinks can have a tendency to chatter, unless you have the ability to run at really slow RPM's. Either one will work in a drill chuck just fine.

I agree with Bender, but when using a single flute you need to make sure your work is secured properly.......otherwise the single flute will just move the work around as it spins. I usually don't use a single flute unless it's with a mill. When used like that, I agree that a single flute gives the best finish.

Most people do not have a mill handy, or a way to properly locate and secure their work, and that is where I would grab a multi-flute, but again Bender is totally correct......SLOW IT DOWN!!! We have so many people come into the shop, chuck up a multi-flute countersink and spin it like a drill bit........Chatter City! Basically if you can't see each flute go by as it spins, you are turning it too fast.

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[rex cars]

i prefer to use a multiflute for hand work. have a carbide 3/8 on a handle for smaller work. Consider carbide if you think you might do some carbon fiber. a HSS c-sink might last for 2 rotations in cf. carbide is hard as hell and as brittle as moms fine china. keep it in a box or case or protected in some way. m.a.ford (i think) is a good brand. be prepared for some sticker shock, but if well taken care of, you will only have to buy it once.

[CadToChrome]

Originally Posted by sim

I'm looking for some 90 degree and 82 degree countersinks to add to my tool collection. Mainly will be countersinking 3mm screw holes in aluminium RC car parts, but occasionally will use them on free machining steel.

What kind of countersinks should I be looking for. I seem to see a whole variety on ebay and some of them are really cheap. Also, they need to fit a collet or will a drill chuck do?

Thanks in advance.

Get the 82 degree for metric and English flat head screws, 90 degree are for aircraft flat head fasteners.

As has been stated by others, single flute work really well, do not run at a fast speed unless your material is secure. Works well with hand drill or drill press. and I agree, multi flute will have a tendency to chatter unless run SLOW.

P.S. Buy a good High speed steel, they will last a very long time and therefore cheap in the long run.

[JeepinDoug]

Manufacturer's name;
Ford single flute
Severance multi-flute

These are the only CS's I buy in this configuration.
Severance single flute are marginally good and Ford multis' are crap.

I should add that Severance carbide single flutes are really good, unlike their HSS.

[Biggons]

I can't speak from a machinist's point of view, so these guys prolly know more than I do. But, from a sheet metal mechanic's perspective, I prefer the brand "Weldon". They are single flute and I've used them on everything from O condition aluminum to inconel and they work great. 1/4" shank on the three most common sizes so they can be used in a collett or in a chuck. If you want something to use in a microstop, you'll have to find some that are threaded. Try looking here www.yardstore.com

[sim]

Thanks for all the help guys. I just paid for a 90 degree 3/8" single flute HSS M.A. Ford on ebay.

Now for the 82 degree. Might settle for 1/4" if I can't get bigger.

[Rubbaneck]

This is a good option from Irwin Tools. http://teamscreamracing.com/catagory...es_and_Springs

[ASSASSINO]

Originally Posted by CadToChrome

Get the 82 degree for metric and English flat head screws, 90 degree are for aircraft flat head fasteners.

Aircraft fasteners use 100° countersinks and not 90°. Also, all metric fasteners use 90° while imperial use 82°.

- Are you planning of just cleaning countersinks or making new ones?
- In what type of material?
- By hand or by drill?
- What diameter fastener do you need it for?

Either way, I would suggest getting a 3-4 lip carbide with a 1/4 straight shank. So you can use it either by hand (for cleaning existing countersink only) in a tap wrench or in a drill chuck. Should run you about $15-$20 for the countersink that's made for 3mm-5mm fasteners.

Hope this helps

[BigSki]

Originally Posted by CadToChrome

Get the 82 degree for metric and English flat head screws, 90 degree are for aircraft flat head fasteners.

we use plenty of 65* aircraft hardware with the product that my company builds, so you just need to be sure that you have the correct c-sink to match the hardware that you use. We manily use Greenfield c-sinks in both HSS and carbide. I know they aren't cheap, that's why the tool crib distributes them instead of having a cabinet for anyone to get into.

If you have a drill press and a vise, you can get decent results with a single flute c-sink. A small spray of cutting oil never hurts, either.

[Ty]

I use my M.A. Ford six flute countersinks everyday at work. MA is the best in my opinion, both single and six flute.

[Mnster]

For what its worth I use the cheapo Harbor freight countersinks in my cordless drill. Good enough for me. Works better then attempting to use a oversize drill bit.

[C*H*U*D]

Originally Posted by Mnster

For what its worth I use the cheapo Harbor freight countersinks in my cordless drill. Good enough for me. Works better then attempting to use a oversize drill bit.

I agree Mnster , the oversize drill bit method really isn't a great idea......especially when trying to countersink in plastic, because it can grab and pull itself completely through in a second.


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[Riksss]

Single flute work nicely with no chatter. Cant remember where I bought mine but they werent expensive ones.