Author Topic: Hex key and hardware question  (Read 1259 times)

Caribsurf

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Hex key and hardware question
« on: April 28, 2020, 09:22:17 AM »
I needed new hex keys to assemble my Fanatic Aero foil.  The original are cheap and don't say the size....The bolts used are sizes M8 and M6 , so I ordered a set of metric t handle hex keys.  I guessed incorrectly that the M8 is 8mm and M6 is 6 mm but obviously this is not the case.  Luckily there were many different sizes, and it turns out the hex keys from the new set that fit the heads of my bolts are the 5 mm and 4 mm....? They do fit, but afraid they aren't exact and I wouldn't want to strip the heads.   Maybe there is a more exact hex key for them

can someone please explain to me what M8 and M6 sizes are/mean?   
thanks for any info



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Wetstuff

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Re: Hex key and hardware question
« Reply #1 on: April 28, 2020, 09:40:00 AM »
Carib,  She can ' splain it better than I can.  I assume (always trouble) the hex insert is limited by the available meat in the head.

https://www.youtube.com/watch?v=66HUDL40EHk


Jim
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clay

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Re: Hex key and hardware question
« Reply #2 on: April 28, 2020, 10:14:45 AM »
I did the same thing, confused by the sizing ordered giant hex keys by accident.

These are what I have now and suspect they will last forever:
https://www.amazon.com/gp/aw/d/B000X1P1VY
https://www.amazon.com/gp/aw/d/B000X1R22K

The trick for me is to make sure the wrench is all the way in the head before tightening, and then turning with downward pressure so the wrench doesn't work itself up and strip the bolt
Aloha, I welcome and appreciate all responses of positivity and good feeling.

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Caribsurf

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Re: Hex key and hardware question
« Reply #3 on: April 28, 2020, 12:17:20 PM »
wetstuff and Clay, thanks for the feedback and info.   I am glad I am not alone with this confusion Clay.


Maybe some Europeans can chime in here as Fanatic based in Germany?
Hobie Raw 8'10"
Jimmy Lewis Kwad 8'7"
L41 Bruce Wayne 8’10”
Jimmy Lewis Flying V foil SUP 6’11”
Fanatic Sky SUP foil SUP 6’6”
Coreban Rocket 10'6"
Hobie 14' race board

Keys Sup

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Re: Hex key and hardware question
« Reply #4 on: April 28, 2020, 12:44:30 PM »
Wera Hex Keys and Screw Drivers are the best.

Dwight (DW)

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Caribsurf

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Re: Hex key and hardware question
« Reply #6 on: April 28, 2020, 01:57:31 PM »
Keys Sup and Dwight thanks..what I was trying to find out is what does M8 and M6 bolts translate to in MM?  what size hex wrench      After a bunch of Google searches, I think I finally figured it out that  the 5mm and 4mm are the sizes for M8 and M6 bolts.

thanks everyone

Dwight that tool looks perfect and I will look for one

Don
Hobie Raw 8'10"
Jimmy Lewis Kwad 8'7"
L41 Bruce Wayne 8’10”
Jimmy Lewis Flying V foil SUP 6’11”
Fanatic Sky SUP foil SUP 6’6”
Coreban Rocket 10'6"
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Dwight (DW)

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Re: Hex key and hardware question
« Reply #7 on: April 28, 2020, 03:13:01 PM »
The stainless screwdriver from McMaster.com are Wera.

Wrench size varies by screw type. Socket head cap is different size from flat head.

Look up the screws on McMaster, click the CAD drawing. Wrench size is there.
« Last Edit: April 28, 2020, 03:15:18 PM by Dwight (DW) »

wingdingjoe

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Re: Hex key and hardware question
« Reply #8 on: April 30, 2020, 04:26:05 PM »
Wow Dwight I never would have thought that the HEX would be a better option than TORX!! You are saying that 100% because its deep enough that the wrench doesnt fall out when you spin it...whilst the TORX falls out easier? Here I was searching all over hells half acre to replace my Hex bolts with TORX...but here in mexico nobody sells TORX bolts and even less in the stainless Steel option.

You havent found then that the TORX tends to STRIP out less than Hex? I get the message that the TOOL should be stainless as well (another impossibility here...id have to buy online and have it imported.)

THanx for the great tips!

Dwight (DW)

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Re: Hex key and hardware question
« Reply #9 on: April 30, 2020, 05:43:38 PM »
Of course Torx is more strip proof, but the Torx wrench is not self supporting when engaged, so you can’t spin it with your finger. That sucks big time. Battery powered drills suck too. Rusted bits, dead battery.

It’s not difficult to use Allen head without any trouble at all. Don’t use a rusty wrench, it will strip out every time. So buy a stainless wrench.



« Last Edit: April 30, 2020, 05:52:13 PM by Dwight (DW) »

clay

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Re: Hex key and hardware question
« Reply #10 on: April 30, 2020, 06:42:54 PM »
I personally do NOT like torx / star heads. 

The main reason is bolts and wrenches are ridiculously hard to find, locally it's dang near impossible to find parts.

Also I find that because the torx key / wrench doesn't sit well in the head it's easier to strip and or break the head and key.

With the Wera hex keys I never strip or break bolts.  Some bolt heads will get rounded, but I have discovered that was mostly because I was lazy with my wrenching and the key wasn't inserted all the way into the head.  Slowing down and taking a few more seconds to tighten makes a big difference for me.
Aloha, I welcome and appreciate all responses of positivity and good feeling.

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Wetstuff

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Re: Hex key and hardware question
« Reply #11 on: May 01, 2020, 05:44:51 AM »
Thanks, Dwight.  Tho' about the same cost of a 37&1/2pc 'Mechanics Tool Set' from Hunan, I am sure it is worth it.  I am an old fan of McC.  Cheers.

Jim
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PonoBill

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Re: Hex key and hardware question
« Reply #12 on: May 01, 2020, 08:41:29 AM »
If you want to tighten a screw repeatedly, a lot of times, then it's tough to beat Torx--simply because of the angle of the torque applied. If you think about fasteners, as I have unfortunately had to do quite a few times, the idea of applying torque to the outer diameter of a screw by sticking something well inside that diameter is not ideal. Given all the inherent limits of this notion, you want the surface you are applying torque to perpendicular to the torque, and you want the torque faces to be at 90 degrees vertically to the torque so the force doesn't push the driver out.

The various screw head types were developed primarily for machine assembly--Phillips being a low torque head, relatively easy to manufacture, self-centering but very easy to strip out since at least 30 percent of the torque force goes to pushing the driver out of the head. There are also several incompatible styles that look identical, most commonly SAE and JIS. If you use an SAE driver in a JIS screw you will strip it out at surprisingly low torque.

Slotted screws can actually take more torque than any other head style, especially the variety called cheese headed, but the driver must fit perfectly and the bit should have sides that are parallel not tapered, and fit the slot snugly at full width. You won't find an inexpensive slotted screwdriver like that anywhere. 

Hex is a lousy design for many reasons--the torque to turn the screw pushes the key out of the hole because more of the turning force goes to deforming the hole than turning the screw--there are NO perpendicular torque faces.  They are not self-centering, can't be cleaned out if you get stuff in it, and weaken the head the most of any design--with square drive a close second. If you want them to last get the squared heads, not rounded--the rounded heads permit more deformation at the top of the hole. Wera hex keys are lovely, but like any long handle or T-handle key they encourage excess torque, and when you turn them on their side in the high leverage direction they become great tools for blowing out the hole. A fine tool, but use them with some caution. I like Klein hex keys the best, and like Wera they cost a hell of a lot more than the cheap stuff. Downright eye-watering in full set, I think I paid fifty bucks for my metric and SAE Wera keys

Torx is slightly better since the lobes align better with the torque and the lobes strengthen the head--it's why they call it Torx. They are expensive to manufacture, are a bitch to clean out, and self-center marginally.

All drive methods represent compromises, which is why there are so many. If I had my druthers all screws would be pentalobe, but that's not going to happen.

As everyone probably knows by now, M6, M8, etc refer to the screw's major diameter, the hex key that fits them depends on who made them and what they made them for, but in all cases that I'm aware of, metric screws take metric drivers. Generally, an M6 takes a 5mm key, but there's no guarantee of that. The same way that a 1/4-20 SAE bolt takes a 5/16" wrench--most times, except when it doesn't.

The choice of tool and hardness comes down to two questions--how much do you trust your mechanical sympathy, and how hard will it be to get the screw out if you bugger the head. A hard hex key will give you the most torque but if it's a lot harder than the head you know what will fail first if you get ham-handed. In a perfect world, we'd be using torque screwdrivers and running these things in carefully by hand. And we'd discard them at the first sign that the head is failing. We don't do that. I have several torque screwdrivers, I have no idea where they are--I haven't seen them in years.

In the unlikely event you want to know a lot about fasteners and their uses I recommend the late, great Carroll Smith's excellent book "Nuts, Bolts, Fasteners and Plumbing Handbook", plumbing in this case meaning race cars, not toilets.
« Last Edit: May 01, 2020, 08:48:23 AM by PonoBill »
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

Caribsurf

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Re: Hex key and hardware question
« Reply #13 on: May 01, 2020, 10:12:48 AM »
Pono you stated "Generally, an M6 takes a 5mm key, but there's no guarantee of that."   

I just bought a set of  Bondus brand Hex t handles. 2mm to 12mm.

 For this particular hex set, the 5mm fits the M8 screw head and the 4mm fits the M6 head.  They seem to fit the head well with no play or wiggle so I am guessing hey are the correct size.
Hobie Raw 8'10"
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Jimmy Lewis Flying V foil SUP 6’11”
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PonoBill

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Re: Hex key and hardware question
« Reply #14 on: May 01, 2020, 10:44:20 AM »
Like I said--no guarantee, but 4mm hex key generally fits the fairly rare M5 screw. Here's the standard table:

https://www.thenutplace.com/files/5814/5926/5468/20HexSocketWrenchSize.pdf

The standard joke in mechanics circles is how 10mm wrenches and 5mm hex keys all disappear (or 7/16" and 3/16" if you work mostly on stuff that's SAE).
« Last Edit: May 01, 2020, 10:48:42 AM by PonoBill »
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

 


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