Star head screws

[LD1]

Robertson is just a square drive IIRC.

While they are better than Phillips by a lot, I don't think they are as good as torx.

Another type out are spline drives. Slot of structural screws are using them. While probably stronger and less likely to strip out than torx, for wood screws I don't see a practical advantage.

 

[JRobyn]

The metallurgy of Torx bits from some suppliers can be questionable for sure. The cam bearing caps on Triumph 900cc triples are notoriously tight and there are numerous stories of bits snapping off and leaving brittle tool-steel shrapnel inside the engine where it is difficult or impossible to extract. I bought a set of the 3/8" drive ones made by Lisle. Good so far!

 

[Creamer]

The Torx heads are great for automated machinery. Hex heads are awful. That is the main reason that Torx heads are being used in automobile assembly.

I have always sworn at Robertson heads. It seems that I strip a lot more of those than that Torx.

 

[bcp]

I love em over even the square drive screws. in order of preference torx, hex (allen), square drive, phillips then common slotted which should be banned from the face of the earth then phillips drives should be done away with.

We could probably do without some others, too.



Bruce

 

[downsizingnow48]

Great chart. I have one to add. I have a box of #8 self drilling/self threading metal screws. They have hex head on the outside and torx on the inside.

 

[LD1]

Great chart. I have one to add. I have a box of #8 self drilling/self threading metal screws. They have hex head on the outside and torx on the inside.

Haven't seen those.

Do you prefer to use the hex, or the torx?

I find a good magnetic nut driver works well. But have never had the pleasure of using torx drive for a sheet-metal screw. Only wood screws and the larger automotive fasteners

 

[Egon]

A few facts on Robertson Screws. It would seem he introduced the recessed head screw back in about 1908. Lots were used on Model T's but stopped as Henry wanted controll of manufacturing but did not get it!

[video]http://www.robertsonscrew.com/history.html[/video]

 

[downsizingnow48]

LD1 here is the link. I use a torx bit, it is slimmer than a hex bit and seems to stay engaged better.

McMaster-Carr

 

[JRobyn]

Nah, there's only one sizing spec - Torx - Wikipedia

But there is now "Super Torx".

I was wrong on this - "Super Torx" is just what Lisle (and maybe some others?) call their high-quality "regular" Torx bits. What I meant to say is that there is now (since 1990), "TORX PLUS".

"A Torx successor, Torx Plus, was introduced about 1990 when the original Torx patent was expiring. The lobes are more square to allow for higher torque and to minimize wear. The name is shortened to IP (Internal Plus) with sizes ranging from 1IP to 100IP [16] (sometimes listed as IP1 to IP100 [17]) and EP (External Plus) with sizes ranging from 1EP to 42EP as well as smaller sizes ranging from H7EP to H2EP and includes five-lobed tamper-resistant variants.[16] The specifications for these licenses are held by Textron. Standard Torx drivers can be used to drive Torx Plus screws, but not to full torque because of the loose fit. Torx Plus drivers will not fit into standard Torx screws."

(From Wikipedia, emphasis added by me)

 

[motownbrowne]

Great chart. I have one to add. I have a box of #8 self drilling/self threading metal screws. They have hex head on the outside and torx on the inside.

Ooooo, those sound fancy!!