automotive 12 point fasteners

[setfocus]

I ran into 12 point caliper bracket to knuckle bolts on a landrover. Where else have you run into 12 point bolts/nuts on a modern light duty car/truck and what sizes? I've heard they're used more for engine internals but I don't do heavy engine work.

The only 12 points I currently have are 12,13,14mm for the front hub bolts on solid axle jeeps and rams. I'm thinking about getting the Tekton shallow metric 12 point impact 1/2" set that goes from 11-24mm with 27, 30, 32 but skips 16, 20, 23.

Has anyone run into a 16mm 12 point bolt/nut on a car/truck? And are the 30, 32mm Tekton sockets deep enough to work on toyota/benz/bmw/audi/vw 12 point axle nuts? Would be nice to kill 2 birds with 1 stone, I don't have any 12 point axle nut sockets and that Tekton set is quite cheap.

I'm also thinking about the Tekton deep 12 point chrome 1/2" set, are the sockets cut deep? Once had to borrow a 12 point deep from a co-worker to change a cylinder head temp sensor on a focus. My snap-on 6 point impact sockets wouldn't fit over the electrical connector, was no room for a wrench or crowfoot... with the valve cover on anyway. Anyone run into other odd situations where a 12 point socket did the trick over a 6 point?

 

[bwringer]

Head bolts and piston rod bolts/nuts. Temp and oil sensors.

On many Toyotas (and probably others) the factory CV axle nut is 12 point 30mm; not a normal impact socket, but common enough to be relatively cheap in any parts store.

 

[Yarpo]

I ran into 12 point caliper bracket to knuckle bolts on a landrover. Where else have you run into 12 point bolts/nuts on a modern light duty car/truck and what sizes? I've heard they're used more for engine internals but I don't do heavy engine work.

The only 12 points I currently have are 12,13,14mm for the front hub bolts on solid axle jeeps and rams. I'm thinking about getting the Tekton shallow metric 12 point impact 1/2" set that goes from 11-24mm with 27, 30, 32 but skips 16, 20, 23.

Has anyone run into a 16mm 12 point bolt/nut on a car/truck? And are the 30, 32mm Tekton sockets deep enough to work on toyota/benz/bmw/audi/vw 12 point axle nuts? Would be nice to kill 2 birds with 1 stone, I don't have any 12 point axle nut sockets and that Tekton set is quite cheap.

I'm also thinking about the Tekton deep 12 point chrome 1/2" set, are the sockets cut deep? Once had to borrow a 12 point deep from a co-worker to change a cylinder head temp sensor on a focus. My snap-on 6 point impact sockets wouldn't fit over the electrical connector, was no room for a wrench or crowfoot... with the valve cover on anyway. Anyone run into other odd situations where a 12 point socket did the trick over a 6 point?

Belt tensioner on a 2017 E300 with the 274 uses a 16mm 12 point. Just did one last week.

 

[2ndGearRubber]

Kia/hyundai ac bracket bolts, caliper bracket bolts on various euros, axle nuts too on euro and toyota. Flywheel and pressure plate bolts are commonly 12pt, lots inside the engine are too obviously. Buy a single 16mm 12 point, you'll find a need. Some of the euros use larger 12 point axle nuts, but 29/30/32 are the common 12 point toyota sizes.

I prefer 12 point for removing sensors, as they're normally cut deeper and have a larger internal volume to accept the electrical connectors.

 

[Mechanical Noise]

12 point bolts attached the rear U joint on Fords.

 

[joe_padavano]

12 point fasteners are typically used where a smaller than normal bolt head or nut is required for clearance without sacrificing torque ability.

 

[Mgdoug3]

Around 2000, I know Dodge used 12 point 10mm bolts for the starter on trucks with the Cummins motor. My truck is an 03 and uses a metric allen plug though.

 

[RedF]

2nd gen dodge trucks use a 14mm to attach the unit bearings to the steering knuckles.

 

[OHMS LAW]

Drive shafts on freightliner and other big trucks

 

[Xcursion88]

Jeep hubs ... wrangler from 87 onward, g.c. , driveshaft yoke to axle yoke flange on many different trucks.

 

[icthruu74]

Water cooled VW pressure plates are maybe 9-10mm 12pt. I forget now.

I had a Saturn that had a 12pt damper bolt, I think it was 23mm (it’s been a awhile). That same Saturn had a couple E-torx head bolts (I believe all GM ecotech 2.2’s has them)

 

[Greg85mcss]

I’ve used a shallow on dozens of toyotas but recently had a venza I actually needed a deep for. Got an astro set on amazon pretty cheap.


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[Tonyuk]

VW clutch assembles, as well as a good few other places.

E-torx are also everywhere, especially on Mercedes and BMW, whereas VAG make more use of spline.

If you dont deal with them often, Halfords pro socket sets are pretty much all 12 point other than their 1/4" stuff. Lifetime warranty, just use them on an impact and change it if it breaks.

 

[MikeF2316]

Turbochargers and exhaust manifolds.

 

[gotwheels]

Please excuse my ignorance. I assume this reference of 12 point fasteners does not use the traditional 12 point socket? What tool is used - spline socket, xzn socket? Thanks for helping the clueless!

 

[Mohawk Dave]

Sideline.... We use all NAS Mil-Spec 12pt on the race trucks. We all went Snap on 7 years ago and never looked back. (I do want Koken stuff just because it's **** though. Lol)

 

[MikeF2316]

Please excuse my ignorance. I assume this reference of 12 point fasteners does not use the traditional 12 point socket? What tool is used - spline socket, xzn socket? Thanks for helping the clueless!

I have never seen an "external" XZN (triple square), only internal. All the 12 point external bolts/nuts I've seen have fit normal 12 point sockets perfectly.

 

[gotwheels]

Thanks MikeF2316 for clarifying foe me type of tool needed. I guess I need to verify what I have in 12 point sockets.

 

[Philbert]

I would say just but the 12 point sockets you need to do the work you are doing and or plan to do.

 

[goforbroke]

Honda’s D-series, B-series, and K-series engines use a 12 point 14mm bolt for the head studs, I believe the F-series does also but I haven’t worked on many of them. The replacement aftermarket ARP head studs for those engines is 12 point as well.
The flywheel and clutch bolts on Honda’s D-B-K series engine use a 12 point bolt as well.

 

[vanapplebomb]

I work on air cooled VWs often, and you will find a 14mm triple square on the pressure relief valve of T4 engines. Also, a lot of the 8mm cv joint bolts had triple squares as well.

Be aware, both triple square and regular twelve points have twelve points, but the profiles are different. What is commonly refered to as a twelve point is two hexagons overlaid, with corner angles of 120 degrees. A triple square is three squares overlaid, so the corner angles are 90 degrees. In my experience, the triple square heads are much more resistant to stripping out than normal twelve point sockets because the force is closer to perpendicular on each of the points.

See attachment for drawing of twelve point and triple square.

 

[Greg85mcss]

Honda’s D-series, B-series, and K-series engines use a 12 point 14mm bolt for the head studs, I believe the F-series does also but I haven’t worked on many of them. The replacement aftermarket ARP head studs for those engines is 12 point as well.
The flywheel and clutch bolts on Honda’s D-B-K series engine use a 12 point bolt as well.

J and r series both have 12 point 14mm head bolts but use a 6 point 10mm for the flywheel/flexplate.


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[engineer2]

Pontiac V8 fuel pump bolts in the 60's and 70's were 12 pt.

 

[Bigblue&Goldie]

Sideline.... We use all NAS Mil-Spec 12pt on the race trucks. We all went Snap on 7 years ago and never looked back. (I do want Koken stuff just because it's **** though. Lol)

We use them on our desert cars also; mostly from RPI. Can't say we've ever had a 12pt fail that I can recall. The only time I've ever had a problem is at Parker 425 last year when we broke a front arm on the 5u car. I started pulling the front shocks off and the ************* Craftsman ratchet we had on our tool bag broke. Luckily I had a 12pt box end wrench. I remember I had to link 2 wrenches together to get enough leverage on the bolt.

 

[darkzero]

Honda’s D-series, B-series, and K-series engines use a 12 point 14mm bolt for the head studs, I believe the F-series does also but I haven’t worked on many of them. The replacement aftermarket ARP head studs for those engines is 12 point as well.
The flywheel and clutch bolts on Honda’s D-B-K series engine use a 12 point bolt as well.

D series & B series OEM head bolts are 6 point. Usually only the aftermarket head studs & bolts & aftermarket connecting rods are 12 point. But yes their flywheel (and flex plate) & pressure plate bolts are 12 point.

 

[goforbroke]

J and r series both have 12 point 14mm head bolts but use a 6 point 10mm for the flywheel/flexplate.
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I figured they did but I wasn’t sure, I know Honda usually doesn’t change damn near anything for decades if it works.

D series & B series OEM head bolts are 6 point. Usually only the aftermarket head studs & bolts & aftermarket connecting rods are 12 point. But yes their flywheel (and flex plate) & pressure plate bolts are 12 point.

That’s strange when I removed the head off my D16Z6(many moons ago) I for sure thought the oem headstuds were 12 point, but I might be confused with my TSX head I removed a few years ago.

 

[Ilikeike]

Lots of ARP 12pt on my first gen Camaro.

 

[darkzero]

This entire car (so they say).

And another that claims all ARP fasteners (where possible I assume)

 

[Mohawk Dave]

We use them on our desert cars also; mostly from RPI. Can't say we've ever had a 12pt fail that I can recall. The only time I've ever had a problem is at Parker 425 last year when we broke a front arm on the 5u car. I started pulling the front shocks off and the ************* Craftsman ratchet we had on our tool bag broke. Luckily I had a 12pt box end wrench. I remember I had to link 2 wrenches together to get enough leverage on the bolt.

When I wrote my post I thought of you and bet myself you use the same hardware. Right on.

And yup, you confirmed why we just use Snap on...(couple other good things mixed in of course, but mostly snappy for hard line stuff)

 

[Bigblue&Goldie]

When I wrote my post I thought of you and bet myself you use the same hardware. Right on.

And yup, you confirmed why we just use Snap on...(couple other good things mixed in of course, but mostly snappy for hard line stuff)

That's funny, I literally replaced my Craftsman ratchets in my mobile pit box with SnapOn!

I also think it's funny that people think ARP makes good hardware. RPI and other MIL Spec bolts are of far better quality.

 

[setfocus]

well I think I'm going to get that tekton 12 point impact 1/2" set for now and buy a cheap 16mm to fill that gap and also maybe a 3/8" 10mm. The top drawer is starting to get tight for space

 

[Mohawk Dave]

That's funny, I literally replaced my Craftsman ratchets in my mobile pit box with SnapOn!

I also think it's funny that people think ARP makes good hardware. RPI and other MIL Spec bolts are of far better quality.

Agreed. We got a local aircraft surplus place where we find all kinds of wild stuff (grab it while you can type deal) and then we have a place called Specialty Fasteners which stock a ton of stuff...all 12pt in shank size increments.

$110 for two 3/4" x 6" bolts is not uncommon. Lol...but they don't fail on a TT or 6100 truck.

I think my 3/4” flex lock nuts are either $4 or $6 bucks each. Don't remember because I just buy it.

I haven't bought from McMaster-Carr, but know they carry both high quality grade 8 and Mil-Spec....pretty good prices when I was casually browsing. BTW, their phone app is AMAZING. I highly recommend it. It's great to have just to see what may work for your application that you didn't even know existed.

 

[Bigblue&Goldie]

Agreed. We got a local aircraft surplus place where we find all kinds of wild stuff (grab it while you can type deal) and then we have a place called Specialty Fasteners which stock a ton of stuff...all 12pt in shank size increments.

$110 for two 3/4" x 6" bolts is not uncommon. Lol...but they don't fail on a TT or 6100 truck.

I think my 3/4” flex lock nuts are either $4 or $6 bucks each. Don't remember because I just buy it.

I haven't bought from McMaster-Carr, but know they carry both high quality grade 8 and Mil-Spec....pretty good prices when I was casually browsing. BTW, their phone app is AMAZING. I highly recommend it. It's great to have just to see what may work for your application that you didn't even know existed.

I'm in AZ, but when I'm at the shop in LA we often go to Luky's in Burbank to get random surplus fasteners and fittings. Sounds like the place you are describing. They also do custom brake lines and hoses. It isn't cheap, but I trust actual aircraft stuff overall "motorsports" stuff any day of the week. Plus, Luky and her family are Mexican, so they love desert racing. They've got awesome pictures all over the shop.

The guy that preps our team's 6100 buys F9 hardware from McMaster. I know that's where our centersection diff bolts come from. I buy a ton of stuff through them for my random projects. My buggy is mostly Grade 8, but like everyone else I use 12pt CV bolts, hub bolts, and trailing arm bolts.

 

[epmills]

Lots of 12pt on newer Mercedes, 21mm on upper control arm ball joints, 36mm front axle nuts.