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12pt SAE bolts....

Buckgnarly

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Anyone ever run into them, and if so, where? Just thinking about it as I have seen metric on cars, but never SAE 12pts.
 
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MotoDave

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Jul 1, 2009
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Ventura, CA
Lots of aerospace fasteners are reduced head 12 point, can't say I've run across them on anything else.
 

Hpozzuoli

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Dec 11, 2013
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Rhode Island
The cat3208 my dad has in his rv has 4 lifting plates on it. They are held on by 12 pointers for some reason. I don't run into them very often with the Vettes unless some ding dong replaced something and didn't have a regular 6 point bolt on hand.
 

Mickey O

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Oct 25, 2009
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Chicago, IL
Harley Davidson motorcycles use SAE 12 points, head bolts and lifter block bolts.
 
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purplezr2

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Jun 1, 2010
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Central MN
I think almost all the applications mentioned are metric, I know the Ford U joints are metric, most diesel driveline 12pts are metric(13mm or 12mm), and I believe HD headbolts are metric. I think NV4500 trans may use 3/8 12pts to hold the back cover on, but it could be 10mm, I don't remember.
 

Chilliwack Murray

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They've been used for years anywhere there is limited real estate for the head of the bolt and tool access like the ujoint straps. They will deliver more torque than an allen head fastener can without damage. They've been used in diesel engine internal fasteners, highway truck differentials since before they were metric. Old (80s) 46,000lb or 48,000lb rockwell diffs with air lockers or two speeds used a 5/8 12pt on a 5/8 bolt for clearance and was guaranteed to bust any wrench but a snap-on back when I worked on them. Every new guy would bust a wrench after insisting their cheap wrenches were just as good and everyone of them bought a SO (in that size at least) after they broke every one in their box.
 

gungatim

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west mich
2nd gen camaros used them on body under hood, also my harley Ironhead uses them on the headbolts...oh, and rod cap nuts on olds rocket 394 motors of early 60's vintage.
 
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rusjack

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Oct 11, 2013
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Ontario, Canada
Lots of the stuff on the two engines I work on (GE cf34 and Rolls Royce BR700) use SAE 12pt fasteners. Jet engines are covered with them - I don't have any 6 point tools at work
 

Bigblue&Goldie

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AZ
Almost all of the suspension and engine components on our Class 1 off road race car are 12pt SAE. Of course, this isn't an OEM application, but they are used extensively in offroad racing because of their high strength and low profile heads.
 

Wakefield

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Arlington VA (but would like to get out to country
They've been used for years anywhere there is limited real estate for the head of the bolt and tool access like the ujoint straps. They will deliver more torque than an allen head fastener can without damage. They've been used in diesel engine internal fasteners, highway truck differentials since before they were metric. Old (80s) 46,000lb or 48,000lb rockwell diffs with air lockers or two speeds used a 5/8 12pt on a 5/8 bolt for clearance and was guaranteed to bust any wrench but a snap-on back when I worked on them. Every new guy would bust a wrench after insisting their cheap wrenches were just as good and everyone of them bought a SO (in that size at least) after they broke every one in their box.

Wonder if a Wright wrench would work!
 

Dynamic86

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Dec 18, 2013
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207
All over a Coe veneer lathe at my plywood plant. Had to by a new set of 12 point sockets to work on the damn thing.
 

00S4Boy

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Feb 4, 2010
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Why do I wanna say chrysler products have them on hubs like a 9/16th.
 

nicksnothereman

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In the Mojave
Anyone ever run into them, and if so, where? Just thinking about it as I have seen metric on cars, but never SAE 12pts.

Spline? They exist. Before they started using torx. I think drivetrain is where you'd find them (mainly). If there were more older (70s and 80s) cars on the road you'd be seeing them much more. Past that...not a whole lot.
 

Deskmechanic

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Aug 17, 2010
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Long Beach, CA
Rear main seal retainer on Chrysler big block (B/RB/Gen II hemi) and slant six from at least 1959 had two long bolts with 12-point 3/8 heads.
 

Karl_B

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Oct 13, 2013
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Killeen, TX
Oldsmobile V8 engines used 12 point nuts on the connecting rods from 1964-1990. I've only run across them a handful of times other than that in my projects.
 

sberry

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Brethren, Michigan
Almost all of the suspension and engine components on our Class 1 off road race car are 12pt SAE. Of course, this isn't an OEM application, but they are used extensively in offroad racing because of their high strength and low profile heads.

Another thing is it reduces the chance of the wrong grade of fastener being reinstalled.
 
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