Shopsmith Forums

bainin wrote:i use them occasionally for cabinet type stuff. My router table build from a few months back used them. They are fast and positionally agnostic...can place them just about anywhere so long as they provide the support you need.

The issues I have with them are :

1) Sometimes the screw doesn't set correctly to align with the pre-drilled hole. Then when you drive the screw in-the clearances are small enough that you can get the screw point popping thru your second piece. Keep a file handy

Its hard to tell visually if you have the screw placed properly in the pre-drilled hole to avoid this.


2) I'm sure there are valid reasons for forcing me to keep the special screw head adapter for my drill - but I'm constantly worried I will lose it. Not sure I see a good reason why these screws couldn't simply use a Philips head.


b

Maybe because Philips are designed to cam out and destroy the screw socket,

The Robertson (square) head is superior in many ways, it is immediately apparent if you have the correct size bit, (with Philips I'm never sure), the screw will stay on the bit without it being magnetic,
Here in Canada everyone uses them.

rpd wrote:

bainin wrote:i use them occasionally for cabinet type stuff. My router table build from a few months back used them. They are fast and positionally agnostic...can place them just about anywhere so long as they provide the support you need.

The issues I have with them are :

1) Sometimes the screw doesn't set correctly to align with the pre-drilled hole. Then when you drive the screw in-the clearances are small enough that you can get the screw point popping thru your second piece. Keep a file handy

Its hard to tell visually if you have the screw placed properly in the pre-drilled hole to avoid this.


2) I'm sure there are valid reasons for forcing me to keep the special screw head adapter for my drill - but I'm constantly worried I will lose it. Not sure I see a good reason why these screws couldn't simply use a Philips head.


b

Maybe because Philips are designed to cam out and destroy the screw socket,

The Robertson (square) head is superior in many ways, it is immediately apparent if you have the correct size bit, (with Philips I'm never sure), the screw will stay on the bit without it being magnetic,
Here in Canada everyone uses them.

I was stationed at CFB Bagotville Quebec in 1980 and spent four years there. You guys had square drive screws back then. I never saw or heard of them until that time. As far as I know they were nowhere in the US. They are absolutely the best screw head available.

As you say there is only one bit that fits for any given screw. With Phillips and straight screws there is no standard for the screw or the screw driver. I think Phillips is the worst. I only buy Robertson drive screws now if I can.

As far as bainin saying they need a special driver, the square driver bits are available every where.

bainin wrote: . . . Not sure I see a good reason why these screws couldn't simply use a philips head.


b

Do the kreg screws have a true phillips head?

JPG wrote:

bainin wrote: . . . Not sure I see a good reason why these screws couldn't simply use a philips head.


b

Do the kreg screws have a true phillips head?

They don't have a Phillips head. They have a square head as stated above.

jsburger wrote:

JPG wrote:

bainin wrote: . . . Not sure I see a good reason why these screws couldn't simply use a philips head.


b

Do the kreg screws have a true phillips head?

They don't have a Phillips head. They have a square head as stated above.

Missed those posts in page 3.

JPG wrote:

jsburger wrote:

JPG wrote:
Do the kreg screws have a true phillips head?

They don't have a Phillips head. They have a square head as stated above.

Missed those posts in page 3.

That is probably the same thing we had a discussion (I reported) a few years ago. If you click on "first new post" and it gives you a post on a new page there are probably new posts on the previous page. When that happens I always go back to the previous page to make sure I didn't miss a post.

It is a defect in the forum software.

I think it is more an issue of MY reaching the end of page n and not realizing there is a page n+1.

JPG wrote:I think it is more an issue of MY reaching the end of page n and not realizing there is a page n+1.

Yes, I do that also but the other issue is definitely there.

thanks for sharing those videos...very interesting to see the ways people come up with to test joint strength. Not sure how the dead weight of a vehicle relates to the racking force of a contented diner leaning back in his chair after polishing off a second helping of pie, but it does say something about the direct up and down shear resistance of the screws. Also, entertaining to watch.

Your bottom line sums it all up. Pocket screws are time savers and when building "utilitarian" pieces, as the woodworker in the other video says, they get the job done. It is surprising though how much stronger the m&t joint is. I wonder sometimes if the old-timers had had the materials we have now if they would have kept up the traditional ways. Imagine Shaker furniture with pocket screws or Rushton canoes slathered in epoxy. I wonder how many would have survived 100 years? Sort of like the old post and beam barns built with pegged joints versus the pole barns of today. I think most pt wood is good for 75 yrs or so, but some of those old barns are going into their third century.

Well, a little off topic there, and maybe a bit curmudgeonly. I do have a new respect for pocket screws after reading this thread, so thanks to all who contributed.

RFGuy wrote: Bottomline, I think for pocket screws it comes down to speed of making the joint versus joint strength. You are giving up a bit of strength for a much faster execution, but that may be acceptable for a given application.

Many years ago I sent off to McFeely's for an assortment of square drive screws after seeing them in a woodworking magazine. I got a fair sized batch of screws and one driver bit. OMG, they were awful... The bit barely entered the head and would just spin out. I tossed the whole mess back in a corner and forgot about them for several years. Then one day I was wanting some screws for a quick job and dug them out again and looked carefully at the problem. That was so long ago that I couldn't even find a proper bit locally. I decided that the problem was the bit instead of the screws and sat down and carefully reground the flats on the bit and fell in love with square drive screws... I buy a lot of construction screws these days and I won't buy anything else but square drive or for some stuff the combo head (SD and Philips). I did one time buy a couple of boxes of what I call "spline drive" screws that came with a new bit in each box. I absolutely detested them. I'm sure they have another name but I can't recall it right now. Today I probably own about 100 square drive bits including a number of the long ones.
I do really love the Kregg system and use it often. I do see people using them dry but I never have. I have always used glue with them. I also use the Kregg screws for a lot of other uses too. I just like the washer head and the way they cut their threads with out splitting. They do tend to be a little pricey but compared to a nice restaurant meal they are a drop in the bucket as a shop expense.


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