I did a repair on a car with a mix of internal torx, external torx, and metric hex fasteners. One particular bolt was an external torx that had to be turned with a wrench and not a socket. It was more difficult than if it were a hex bolt and there are a couple of reasons why.

First there is of course not an open end version of external torx wrenches. It magnified one of the advantages of open/box hex wrenches in that the open end can be manipulated in a range of angles. An attribute that is often utilized with open end hex wrenches that isn't really noticed. Also nothing beats the speed of turning hex bolts that are between box end loosening and still not finger loose than an open end wrench.

The second external torx wrench problem which is also a slight problem when using sockets, is the precision fit on the fastener. The wrench must go on with more precise alignment than hex box ends, it must be perfect. The fit is so perfect that even when it is on partway, it takes further precise alignment to fully engage the wrench onto the torx head.

Not a big fan of E-Torx, but from a design point of view it allows higher torques using a smaller head. I push the design guys in my company not to use them if they can avoid it, but space constraints sometimes make them unavoidable.

Of course, when we manufacture with them we ensure clear access for sockets, it's when you are trying to do repairs that you run into problems.

I watch engine tear down videos from time-to-time and am often dismayed by the variety of bolts one might see in modern automobile engines, hex, torx, e-torx, and what's this? triple square? both internal and external? I swear they are in collusion with the tool manufactures to require every home and pro mechanic to buy every possible socket/tip that has ever been specified. And don't get me started on Phillips vs. Posidrive, at least they could adopt a standard set of marking the damn things!

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Originally posted by architect:
I swear they are in collusion with the tool manufactures to require every home and pro mechanic to buy every possible socket/tip that has ever been specified.

I'm convinced it's conspiracy to prevent & discourage home mechanics from working on their own stuff, which forces them to use manufacturer-approved professionals. The professionals then have to shell out for obscure tools, which keeps tool trucks like Snap-on in business, and also charge higher labor rates for longer billable job times.

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And don't get me started on Phillips vs. Posidrive, at least they could adopt a standard set of marking the damn things!

You forgot JIS, another "+" shaped fastener head. All of them need to be phased out, as they're all inferior to Allen, Robertson, & Torx. All '+' shaped screws are designed to cam out, which sucks when you have a stuck screw.

E-torx box ratchets

Also available are non-ratcheting box ends, with or without 15° offset heads. If not too tight, a six-point box end or socket can be used. Spline drive will also turn these, but can bite in and get stuck on the initial breaking loose. Also, there are Torx and Torx Plus.

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triple square?

Volkswagen and Audi have a fetish for those. Some are even "tamper-proof", i.e., a little peg in the center of the fastener corresponding to a little hole in the tool. I needed one of the latter for a VW SUV's brake calipers. I don't think I used it since. It cost me nearly what I made on the job. Also fun - similar to internal Torx - when they fill up with rust, dirt or grease.

https://en.wikipedia.org/wiki/List_of_screw_drives

quote:

Originally posted by iron chef:
You forgot JIS, another "+" shaped fastener head. All of them need to be phased out, as they're all inferior to Allen, Robertson, & Torx. All '+' shaped screws are designed to cam out, which sucks when you have a stuck screw.

I didn't forget them, but I come across JIS etc. much less frequently.

As for the "designed to cam out," perhaps they could have chosen a torque value below the yield point of the steels used in fasteners so that "cam out" does not include "distort and destroy the bearing surfaces of the fastener?"

IME it is far easier to ruin a phillips head screw by digging out the cross than it is to do the same to an equivalent hex "key," or round off a hex head bolt.

And my god... Metric or SAE, shit, just pick one for your equipment build and stick with it!

And you shouldn't get me started on automotive electrical connectors... Damn, standardize the freaking things already so we can figure out how to actually disconnect the freaking things when you can hardly access or even see them.

According to AI... an average new car can have 700 or more electrical connection.

JIS may have contributed to or been the reason Japanese motorcycle crankcase screws gave me such a hard time. I was using a regular #3 Phillips. (This was circa 1978, so forgive me for not knowing then what I know now.)

Now about that little bit called Reed & Prince...

Then there is this little nugget of joy:

I purchased my motorcycle impact driver because of JIS. Philips and JIS only play well together if you are free running a screw in or out, when it's tight you need the real thing.

In regards to Torx there are some sizes where improvised tools will work. I have used standard SAE or Metric 12 point box end wrenches to loosen external Torx by using a trial and error approach. It's all a matter of seeing a tight fit between wrench and the "points" on the Torx end.

As for Allen, they did have the first patent for a Hex Socket Cap Screw Unbraco followed up with their own version a year later. Today the proper name for a hex tool for these screws is a Hex Key and it is NOT an Allen Wrench.

Before Torx bits were a thing, GM had a 'six point hexlobular' fasteners.

Had to go buy the special bit to work on any seat belts or door jams.

They aren't compatible with Torx in any way other than guessing wrong.

At least spline sockets have mostly been left with airplanes...

quote:

Originally posted by iron chef:

quote:

Originally posted by architect:
I swear they are in collusion with the tool manufactures to require every home and pro mechanic to buy every possible socket/tip that has ever been specified.

I'm convinced it's conspiracy to prevent & discourage home mechanics from working on their own stuff, which forces them to use manufacturer-approved professionals. The professionals then have to shell out for obscure tools, which keeps tool trucks like Snap-on in business, and also charge higher labor rates for longer billable job times.

No I haven't heard that come up once during design reviews in the industry. The service guys push to make things as easy as possible to repair, but they are behind manufacturing (me), and design requirements.

Hex flange head capscrews are common and cost effective. But sometimes the bolt head or the socket that I specify for manufacturing will interfere with other stuff, which pushes use towards internal hex or torx, or sometimes e-torx because the head is smaller for a given bolt size. Then there is clamp load of the joint, and bolt underhead stresses, which are affected by distortion and deflection of the bolt head under load.

Trust me we push for simple and common bolt heads wherever we can, but there are many constraints that affect what is used.

When I was younger I knew that the tool I actually needed was available, but I had no idea how to find it. Now older I know both that the tool I need is available and I can find it, but I will be faced with a completely astonishing array of where to get it and at what quality level.
I am convinced at this point that you can get everything you need. And if a you tube addict have to sort through hundreds of videos telling you who to get it from...