Did you know that on the BT3000 . . .

[leehljp]

That some of the screws for the BT3000/3100 are Tri-sided? This could have been mentioned way back when, but I never noticed that, or at least I don't remember it.

I took my BT3000 apart just before I left Japan - sides, motor / blade housing off; top off from the housing, the bevel gear, etc. Well, I am just now putting it back together. All screws were seperated into little bags according to its particular function. Today, I finally had some time to put it together and I noticed that one of the screws looked funny. Then I noticed several. Those that thread into aluminum are kinda tri-sided.

Kinda proud of myself. I did not have a manual but got it together without a hitch. Two small blunders - the front switch - the box behind the wall I initially installed it upside down, but quickly discovered the problem as I tried to install the side plug in. Only took a minuted to fix. The front lever that changes from Bevel to Height, I put it on at the wrong angle, as I was re-building it up side down. I installed the lever to hang straight down when locked, but discovered it needs to be at an angle. Not a big problem, I will fix that next week. I haven't put the toggle levers for the rails on and of course I have not squared it. I will mount it on a Bosch gravity rise stand.

[Black wallnut]

I read somewhere that the tri-sided screws were self tapping. Guess the idea is they swage threads into the aluminum.

[EngrChrisSaw]

Yes, they are self-tapping, but I also heard the screws will not have the same gripping power before removal. In worst cases, drilling and taping with a larger screw can be necessary.

[LCHIEN]

Huh, Hank?

You mean they're self-tapping with three cutters on the threads?

Or a head with a tri-wing (Y-shaped recess like a phillips but with three instead of four)

or a head with Triangle recess?

I presume you mean self-tapping with three cutters. I suppose the cutters slot/recess are for cuttings relief. The more the easier it would be to cut.

[leehljp]

Huh, Hank?

You mean they're self-tapping with three cutters on the threads?

Or a head with a tri-wing (Y-shaped recess like a phillips but with three instead of four)

or a head with Triangle recess?

I presume you mean self-tapping with three cutters. I suppose the cutters slot/recess are for cuttings relief. The more the easier it would be to cut.

The main shaft/body of the screw is kinda triangular shaped. It is a rounded over triagular, and obvious when looking specifically at the body. The wings/cutters are more round. I have a long day today but tomorrow (Tuesday evening) I will be able to hopefully take a picture of one of the screws. Although it is together, I can take one out easily enough and photo it.

[cabinetman]

They are split self tapping screws. The splits allow for clearing if there is a collection of material.

.

[Black wallnut]

They are split self tapping screws. The splits allow for clearing if there is a collection of material.

.

Nice guess but wrong.

[woodturner]

Those that thread into aluminum are kinda tri-sided.

I think you are referring to trilobular thread rolling screws something like these. The shaft cross section is not round but more triangular with rounded corners.

[leehljp]

I think you are referring to trilobular thread rolling screws something like these. The shaft cross section is not round but more triangular with rounded corners.

That is very close, if not the same. I am not at home and won't be there until late tonight. It will be tomorrow evening before I have time to check and photograph one.

[JR]

"trilobular"

A new word for my thesaurus. It sounds like something I would make up, but use anway because it is self-desribing.