Thread: Metric?

I bought a straight "12 mm" bit from Bunnings only to find that after routing several grooves that it was actually 1/2". When I mentioned it to the guy in the tool shop he was totally disinterested.

So don't believe everything you read.

I wouldn't stress too much about finding metric bits. The majority of the router bits that I use are imperial sizes. But an imperial size do have a metric size 1/2" = 12.7, 3/4"=19.05 etc etc. I don't ever recall using a set of round over bits which were not imperial sizes. And the act of sharpening a router bit reduces the cutting diameter anyways. I have had CNC bits start at 18mm and we had them sharpened all the way down to about 13mm and any size in between

For cutting mortises, I like carbide upcut spiral bits. They can be very expensive, especially when you get large diameter extra long bits. But for a 1/4" mortise which I often use, the bits are about 28bux I think, maybe it is 22bux I prefer the shank of the bit to match the diameter of the cutting edge. So for a 1/2" shank, I would like to use a 1/2" spiral bit. Not a 12mm spiral with a 1/2" shank. The reason is because the 12mm on 1/2" shank is simply the same piece of carbide made slightly smaller/weaker.

If you are really new with a router, I highly recommend NOT going out and buying all the router bits you think might come in useful one day. Just buy a cheap and nasty set which contain a few straight bits, a roundover or two, a champher bit, dovetail bit, classical bit, ogee bit. The cheap sets truely are garbage and easily break, but after time you can replace the ones which have timber crud stuck to them due to use and not replace the ones which are still shiny and fresh due to never being used.

So is it OK to buy cheap router bits on eBay that I assume come from China?

Originally Posted by DaveVman

So is it OK to buy cheap router bits on eBay that I assume come from China?

Yes its OK to buy them as long as you don't expect them to last and if they do consider yourself lucky.

A set something like this would be a good "sample pack" to see which profiles you actually need. At a $1.66/bit it's a pretty cheap entry point. Because the same bits of a quality manufacture would run about $150-180 rough guess off the top of my head. I have a pack of these and I have broken a few of the straight bits, never used the dovetail or roman ogee. used the vee groove once and the cove bit about 2-3 times.

https://www.bunnings.com.au/craftrig...t-set_p6370152

Originally Posted by DaveVman

Hi all! I am a complete novice to routing. I've literally never used one. (Although wanted to for years.)
Hence sorry in advance for the super basic questions.
So great news I now have my first ever router! Yay!! I took some advice from this forum and went for a medium size one that can be mounted to a table in the future. It is the Triton 1400W TRI-MOF001.

Now I'm looking at bits but I don't know the first thing about router bits.
One of the many things that puzzles me, is that there appears to be so many imperial bits around and little metric.
I understand the the shanks are standard to 1/4 and 1/2 inch. However anything I cut will be in metric if humanly possible.

something to be aware of

Router bits are available with shanks sized for 6 mm, 1/4" (=6.35 mm), 8 mm, 3/8", 12 mm, 1/2" (=12.7 mm) collets.

a 6 mm shank CANNOT be used in a 1/4" collet and vice versa, no matter what the nice bloke at the Green shed may say.
likewise, 12 mm bits can't be used in a 1/2" collet and vice versa.

Some times 12 mm will be rounded up to 1/2", and sometimes 1/2" will be rounded down to 12 mm. Just something to be aware of.

The vast majority are 1/4" and 1/2" shank and it's pretty safe to assume that all cutting dimensions are going to be imperial unless they are specifically labelled as metric; not just mm, but specifically metric. Carbitool has an 'M' suffix on the tool code for their straight bits

Also note that solid carbide spiral bits are the same size shank as their cutting size, so a 6mm bit has a 6mm shank and a 1/4" bit has a 1/4" shank. This is, at least for the big name industrial brands (Carbitool, Leitz, Leuco), always true, so if you want a 12mm bit you need to find a 12mm collet to go with it.

I've used the set I purchased from Timbecon for years and years. I reckon they're good value for the dollar. When I've blunted/worn one out I replace with a top quality one, as I know that's one I'll use..

https://www.timbecon.com.au/routing/...outer-bit-sets

All great advice above. Just to add, if you go on GraysOnline you may see kits of router bits at seemingly good prices. Just be aware that all the ones I've checked out have had 8mm shanks.
The only one I have that's not 1/2" or 1/4" shank is a 3/8" spiral upcut I required for a special task.

David's set from Timbercon seems pretty good. I would probably have used all of those except the dovetail at one time or another. The only thing is I would have bought them one at a time in 1/4". I have now bought another set in 8mm and it has cost me $$'s.

Thanks for all the helpful advice. As usual I over think things. I realised I just need to cut something and I'll know twice as much as any research.

I needed a 18mm closed slot in a piece. So I went to Bunnings and they had a 18mm straight bit. Too easy.

I attached the good edge guide that comes with the triton router and I set up a jig with stops to make it as idiot proof for myself as possible. I set the depth stops. Cut the slot about 2mm deep each pass.
Exactly what I wanted.

One mistake I think I made was plunging the router while stationary. There are some burn marks and I suspect this it how they occured. I suspect I need to move the router and plunge the bit into the wood at the same time. Would that be correct?

There are differences between a bit that can be plunged into timber and bits which can't. Straight bits which can plunge have a piece of carbide across the bottom of the bit which will cut/scrape away timber as you plunge. But normal straight bits simply have the two carbide tips and no cutting section at the bottom of the bit. As you say, you can just plunge while moving forwards and that works well enough. Just be aware the timber you fail to remove during the ramping plunge will be cut as a climb cut and the router might want to race off towards the edge guide.

If you do go with some cheap Chinese treat them lightly, when I bought my first router I bought some cheap bits and went crazy routing hardwood and a couple of the heads fell off.
I also learned that if I put my router down on the switch side it would turn on and jump off whatever it was sitting on, thanks Ryobi

Plunging on the router table gives me the willies.

One thing to know is that you don't need an 18mm bit to make an 18mm dado... You can use any bit that is smaller and just do two passes. Watch the rotation and feed direction. This is critical unless you want to launch your work across the shed like a rail gun.

There are some good videos and charts on feed direction, both for hand work and table work. It's easy to get them wrong. A router is a powerful beastie and needs respect. I know a guy who only last fortnight fed his hand into a router bit. His fingers are a gruesome mess. Respect...

My stash is now very eclectic. I started with some cheapies thinking the Big Names were ripping me, but with router bits it definitely is a case of paying for what you get. I'm lucky to not have broken a big bit, but it's easy to imagine a flying 18000 rpm hunk of metal wanting to find some meat to imbed itself in

My collection is now comprised of Carbitool (love them), Rockler (love them), some carbides off Aldav (love them. He is a forum member), a set from Schwartz (are they still around?), Yonico (cheap!) and Freud (OMG are they nice). There are a few bits from a few other retailers such as Carbatec, Festool (feel the burn $$), triton (inherited these from a mate) and Timbecon (top blokes).

Carbide is so important. It used to be an option, but it's now cheap enough never to consider non-carbides, unless it's a specialised bit somehow. It cuts so smoothly and stays sharp for ever.

Carbitool is an amazing company. Have a flick though their online catalogue. They will also post you a dead tree version if you ask. There are many good online retailers and the prices are excellent.