Router Bit Question

[BornKilr]

Hopefully any router users here can answer a few questions. I inherited a router and numerous bits. Most of them I know what they're for but a few I'm not sure. I looked online and figured out little more, but still not sure how to use several.

In the first pic, what is the one with the U shaped profile (2nd from left)? It looks like straight cut bit, but not sure why the gap in the middle


In this pic, 2nd from right, its angled at top, but the side of the bit also has a cutting edge. What's it for?



And the last pic, I know these are for edge shaping, but for the ones with no shafts - can I buy plain 1/4" shafts and screw them onto? And do they need to have a bearing? Some of the ones I saw online did



Thanks for any help

 

[swgeek]

I've done a lot of routing but the first bit has me stumped. The second bit is meant to plunge through a material and then make a cut using the cutter on the side of the bit. like if you were rough cutting a sink opening. And the third one(s) I've never seen profile bits without a shaft.

 

[hdtheater]

The first one looks to be a plug cutter. If you had drilled a 1/4” hole in wood and wanted to “plug” it with wood, this is how you would cut your own plug out of the same wood.

On the third pic, you can get a standard size shaft and install different cutting heads on them. I used to have a set, but I don’t see them too much these days. I think it was an idea to make bits cheaper 30 years ago. Nowadays manufacturing has brought the price down to where it isn’t needed. I always had quality issues with them and is why I stopped using them.

 

[BornKilr]

The first one looks to be a plug cutter. If you had drilled a 1/4” hole in wood and wanted to “plug” it with wood, this is how you would cut your own plug out of the same wood.

On the third pic, you can get a standard size shaft and install different cutting heads on them. I used to have a set, but I don’t see them too much these days. I think it was an idea to make bits cheaper 30 years ago.

Ahh, that makes sense on the first one. I'll have to try it out now

And yes, this is and old set of bits from Craftsman. A friends father owned it long ago. If I can't find shafts at hardware stores, I'll try on online for and older set.

Thanks for the responses. I think this answers my questions

 

[mash3d]

Some of those look more like End mills used in CNC machining. This page might help some http://mindworks.shoutwiki.com/wiki/Cutter_Types_(Mill)