4 ms·

Ugh, except Pozidriv will still cam and tear up their own screws, and same with Phillips. That's the secret to this tidbit of information that is never included

Ugh, except Pozidriv will still cam and tear up their own screws, and same with Phillips. That's the secret to this tidbit of information that is never included. They're both trash fasteners when used with a slightly different driver, but they're also trash even when used correctly. Robertson for life. When I was young I had a job assembling furniture and that, along with a couple Allen socket fasteners, was the only thing we used. Phillips fasteners that came with assemblies went straight into metal recycling to hopefully get born again as something worthwhile. You can practically drive a Robertson head straight through the center of the Earth with the amount of torque it handles. Never have to waste time drilling pilot holes. If I was made dictator for a day, I'd immediately outlaw Phillips and Pozidriv. Even flat head is better than those pieces of junk. There are a lot of Phillips fasteners that will also fit a Robertson bit. Just try both with the same screw. It's ludicrous how instantly you'll realize the Robertson is better.

devy 8y ago
> Even flat head is better than those pieces of junk. I would argue that flat head is the worst. They are not designed to be used with power tools.
- vertexFarm 8y ago
  Phillips isn't properly designed for power or hand tools. If it strips with a screwdriver, it's definitely going to strip with a drill. I've rarely seen power-driven Phillips screws that didn't have some sign of stripping, even using torque limiters and even on things fresh from the factory. At least flat head takes uneven torque from hand tools well. It also allows improvised tools to be used in the field. If I'm working on say an off-road vehicle like a dirt bike, I'm going to tend to use just one size of hex bolt (usually 10mm) and flat heads for the screws.
  - devy 8y ago
    I am not arguing for Philips. But flat head has 2 less contact surfaces so definitely even more easily to cam-out.
    - zrobotics 8y ago
      Nope, you are confused about the meaning of cam-out. Flat head is actually significantly less likely to cam out than pretty much any screw fastener type besides inverted hex (allen). Cam out is when the torque applied acts to ramp the driver out of the fastener. The problem with flat head is that drivers do not self center, making them poor choices for power tools. There's a reason flat head screws are still used extensively in firearms manufacture, and it definitely isn't a manufacturing convenience. Carefully driving a flathead screw is much less likely to damage the finish of the fastener, provided the correct driver is used.
      - devy 8y ago
        Ah-ha, I might have mixed up with the screw "stripping" with cam-out but repeatedly cam-out is definitely the main reason to create a stripped screw. Evidently, the cam-out nature of the Philips screw is by design[1] to enable torque-limited application to prevent over-tightening, so it's a feature not a defect! [1]: https://en.wikipedia.org/wiki/Cam_out https://en.wikipedia.org/wiki/Cam_out
Lionsion 8y ago
> Ugh, except Pozidriv will still cam and tear up their own screws, and same with Phillips. That's true, but using a Phillips screwdriver with a Pozidriv screw is worse than either system by itself. Robertson may be objectively better, but that's irrelevant to my point. I was I was addressing was one of confusion. I think your comment more properly belongs at the root than as a response to mine.
- vertexFarm 8y ago
  Fair enough, You're probably right.
antisthenes 8y ago
Last time I tried to use a Robertson screw from Home Depot in a heavy duty application (building an AC frame and decking), it cammed out and the square opening in the screw literally became round. I tried compensating by applying more downward force, but eventually it was still camming out and the bit itself became a cylinder. It maybe better, but if the manufacturing quality is garbage, it's just as useless as the other ones. I've only been using torx screws from 2012 onward. Never cammed out once and I'm still using 5 year old bits (they work like new)
- ibdf 8y ago
  Thanks for the feedback. I too switched to Robertson's but found no difference. It must be the quality of the screws and not the shape.
- vertexFarm 8y ago
  Huh. I've never had that happen once out of literally thousands of screws from all kinds of different sources, including HD. Should be impossible for it to cam because the walls of the cavity are perpendicular. There's no thrust force being generated. Maybe it was just a really bad batch?
  - mindslight 8y ago
    I have some R2 stainless "decking" (read: general construction) screws, and a standard consumer cordless impact driver generates enough transient torque to actually deform the cavity. Which even then results in the bit being "sticky" to pull out. I would imagine after several use cycles, the drive would be completely stripped.
- deleted 8y ago
  [deleted]
thunfischbrot 8y ago
While I generally agree that neither are great (I prefer Torx), are they not designed to protect whatever it is you are fastening from over-tightening bolts?

devy 8y ago

> Even flat head is better than those pieces of junk. I would argue that flat head is the worst. They are not designed to be used with power tools.

vertexFarm 8y ago
Phillips isn't properly designed for power or hand tools. If it strips with a screwdriver, it's definitely going to strip with a drill. I've rarely seen power-driven Phillips screws that didn't have some sign of stripping, even using torque limiters and even on things fresh from the factory. At least flat head takes uneven torque from hand tools well. It also allows improvised tools to be used in the field. If I'm working on say an off-road vehicle like a dirt bike, I'm going to tend to use just one size of hex bolt (usually 10mm) and flat heads for the screws.
- devy 8y ago
  I am not arguing for Philips. But flat head has 2 less contact surfaces so definitely even more easily to cam-out.
  - zrobotics 8y ago
    Nope, you are confused about the meaning of cam-out. Flat head is actually significantly less likely to cam out than pretty much any screw fastener type besides inverted hex (allen). Cam out is when the torque applied acts to ramp the driver out of the fastener. The problem with flat head is that drivers do not self center, making them poor choices for power tools. There's a reason flat head screws are still used extensively in firearms manufacture, and it definitely isn't a manufacturing convenience. Carefully driving a flathead screw is much less likely to damage the finish of the fastener, provided the correct driver is used.
    - devy 8y ago
      Ah-ha, I might have mixed up with the screw "stripping" with cam-out but repeatedly cam-out is definitely the main reason to create a stripped screw. Evidently, the cam-out nature of the Philips screw is by design[1] to enable torque-limited application to prevent over-tightening, so it's a feature not a defect! [1]: https://en.wikipedia.org/wiki/Cam_out https://en.wikipedia.org/wiki/Cam_out

Lionsion 8y ago

> Ugh, except Pozidriv will still cam and tear up their own screws, and same with Phillips. That's true, but using a Phillips screwdriver with a Pozidriv screw is worse than either system by itself. Robertson may be objectively better, but that's irrelevant to my point. I was I was addressing was one of confusion. I think your comment more properly belongs at the root than as a response to mine.

vertexFarm 8y ago
Fair enough, You're probably right.

antisthenes 8y ago

Last time I tried to use a Robertson screw from Home Depot in a heavy duty application (building an AC frame and decking), it cammed out and the square opening in the screw literally became round. I tried compensating by applying more downward force, but eventually it was still camming out and the bit itself became a cylinder. It maybe better, but if the manufacturing quality is garbage, it's just as useless as the other ones. I've only been using torx screws from 2012 onward. Never cammed out once and I'm still using 5 year old bits (they work like new)

ibdf 8y ago
Thanks for the feedback. I too switched to Robertson's but found no difference. It must be the quality of the screws and not the shape.
vertexFarm 8y ago
Huh. I've never had that happen once out of literally thousands of screws from all kinds of different sources, including HD. Should be impossible for it to cam because the walls of the cavity are perpendicular. There's no thrust force being generated. Maybe it was just a really bad batch?
- mindslight 8y ago
  I have some R2 stainless "decking" (read: general construction) screws, and a standard consumer cordless impact driver generates enough transient torque to actually deform the cavity. Which even then results in the bit being "sticky" to pull out. I would imagine after several use cycles, the drive would be completely stripped.
deleted 8y ago
[deleted]

thunfischbrot 8y ago

While I generally agree that neither are great (I prefer Torx), are they not designed to protect whatever it is you are fastening from over-tightening bolts?