The 20mm bolt head ... what ?

[voidptr]

Noob here first message

I'm used to live with SAE and metrics, and I thought I found all different standards for metric over the years ...
Metric standards size

but I was wrong now this week I found this bolt head ...
0.774" or 19.54mm, right between 3/4 and 13/16 and 19mm and 21mm
why ???? where is that engineer who designed that !!! why used a 20mm ?!

it use for a kindof hitch lock for my bicycle rack so nothing really...
why not use a 19 or 3/4 ????

so it seems there is 20mm socket after all...
but I decided to use the power of my bench grinder and transmute that silly bolt to a 3/4"

did you ever see 20mm bolt head somewhere ?

 

[1950mercury]

Yes thats why they make 20mm sockets and wrenches

 

[Welderguy24]

If my memory serves me correctly, ISX Cummins cam bolts, one is 19 and one is 20. Also C7 CAT head bolts are 20mm 12 pt.

Sent from my Icom IC-2200H using a HM-133V microphone.

 

[Manny2_0]

20mm came in my craftsman usa 52pc 3/8 socket set
and in my 14pc craftsman metric wrench set

 

[DanInVA]

I haven't come across a fastener that was supposed to be a 20 in my travels, but a 20mm socket is aces for getting off swollen 19mm chrome capped lug nuts

 

[APEowner]

I can't say as I've kept track but I just looked at a couple of my 20mm sockets and they've clearly been used.

 

[gigamel]

20mm is to big for 19.5mm
This is what you need
25/32" = 19.8mm

 

[Adam.C]

Noob here first message

I'm used to live with SAE and metrics, and I thought I found all different standards for metric over the years ...
Metric standards size

but I was wrong now this week I found this bolt head ...
0.774" or 19.54mm, right between 3/4 and 13/16 and 19mm and 21mm
why ???? where is that engineer who designed that !!! why used a 20mm ?!

it use for a kindof hitch lock for my bicycle rack so nothing really...
why not use a 19 or 3/4 ????

so it seems there is 20mm socket after all...
but I decided to use the power of my bench grinder and transmute that silly bolt to a 3/4"

did you ever see 20mm bolt head somewhere ?

There is no standard bolt with a 20mm or a 19.5mm head. Throw that POS away and replace it with a real bolt before it hurts somebody. If they can't get the head machined properly, do you think they cared about the material?

 

[Jim C.]

20mm is to big for 19.5mm
This is what you need
25/32" = 19.8mm

You beat me to the 25/32" answer. A while back, I ran across a 25/32" nut on an old USA made wood working machine from the 1950s. All the fasteners were SAE but this one nut just didn't fit any of my SAE wrenches quite right. I tried a few metric wrenches and discovered that a 20mm was almost a perfect fit. Finally it occurred to me that the nut was probably sized on a 1/32" increment. To make a long story short, what gigamel said.^^^^^^ Try a 25/32" wrench.

Jim C.

 

[BDT/NWMN]

Our two little footsies cover less than a square foot of a very large planet.... There is nobody that has seen it all... That 20MM size, along with the 16MM is not included in many sets sold in the USA, but somebody is using them somewhere on something...The tool companies build them for a reason.. Part of the "fun" is coming across a need for one and not having it...

 

[brownbagg]

why not just buy a 20mm socket. harbor freight and sears has ton of them. didn't somebody once say, "right tool for the right job"

 

[n8n]

Actually I couldn't find a Craftsman 6 point 20mm 3/8"... ended up buying a Snap-On one off eBay. Kinda stupid because it'll likely be the least used socket, but I couldn't abide the missing space on the socket rail.

 

[Fretters]

Actually I couldn't find a Craftsman 6 point 20mm 3/8"... ended up buying a Snap-On one off eBay. Kinda stupid because it'll likely be the least used socket, but I couldn't abide the missing space on the socket rail.

You're really not helping the cause regarding the OCD suggestions which are bandied about on here on occasion.

 

[BDT/NWMN]

Actually I couldn't find a Craftsman 6 point 20mm 3/8"... ended up buying a Snap-On one off eBay. Kinda stupid because it'll likely be the least used socket, but I couldn't abide the missing space on the socket rail.

Craftsman 43580 is the 3/8" drive 20MM six point that I have.. It came in a set a couple years ago....

 

[gigamel]

As far as I know 20mm has never ever been part of any standard - but 25/32" = 19.8mm is fairly common on older cars and machines.

 

[cjn1014]

Yakima rack?

 

[Wrench 2201]

I have seen 20mm stuff on a few automotive applications. The line nut for the hydraulic cooling fan on some Jeep Grand Cherokees (which you really need a line nut crow foot for ) and the alignment cams on some Audis both require 20mm stuff.

 

[gigamel]

Btw I completely agree with Adam C. your bolt is most likely a dud - very unlikely that anybody would design a bolt with a 25/32" head in 2015 - it's metric right? M10 or M12?

 

[warmpancakes]

Yakima rack?

Don't think so the bottom shoulder on that bolt look like a king rack and they are rebranded for about 50 different companies

 

[Flat-rate]

Metal fuel filters on GM fuel injected cars from the 80's up to 2000 or so are 20 mm.

 

[steed andersen]

I still use 20mm & 25/32" once in a blue moon. But I work on a wide range of equipment dating from the 60's to the present. It bugs me badly when I buy a set of sockets or wrenches without those sizes.

 

[voidptr]

20mm is to big for 19.5mm
This is what you need
25/32" = 19.8mm

I did thought about that, I remember my father had the complete x/32 set, old tractors had need for them, now I still understand that we can have 11/32 and smaller but no more need for the bigger set, what the difference does is really make to use 25/32 or to use 13/16 in new design...

Again I guess in my case nothing at all(btw other nuts are SAE on the rack), here a complete pic of the bolt, it is specifically made has a lock and will be tight by hand to lock my bicycle rack in place into my car's hitch, so having 3/4 (as I grinded it) will be just more user friendly !

yeap In fact in might be a dud bolt !!! lol

 

[old_biker]

one of my pet peeves is a 7/16 allen wrench, try to find one, almost non existing, most tool companies go fro 3/8" to 1/2 & skip the 7/16, but was common on many Harleys for decades.

 

[voidptr]

one of my pet peeves is a 7/16 allen wrench, try to find one, almost non existing, most tool companies go fro 3/8" to 1/2 & skip the 7/16, but was common on many Harleys for decades.

Like this ?

http://www.allenhex.com/l-keys/allen-57031d-7-16-short-arm-l-hex-key.html

 

[old_biker]

yes, a little short, but could use, I have a handful of vintage ones I picked up at flea markets, during my life, & if you buy a new one from a place as a speciality tool last I looked it was nearly $50 for one.

 

[rob1200]

Actually I couldn't find a Craftsman 6 point 20mm 3/8"... ended up buying a Snap-On one off eBay. Kinda stupid because it'll likely be the least used socket, but I couldn't abide the missing space on the socket rail.

Craftsman 43580 is the 3/8" drive 20MM six point that I have.. It came in a set a couple years ago....

Craftsman 45863 is available individually, currently $3.99:

Craftsman 20mm Easy-To-Read Socket, 6 pt. 3/8 in. drive

 

[n8n]

The open stock displays in all the stores near me didn't even have a hook for 20mm *shrug* in an case I have the SO one so I'm hopefully set for the rest of my life...

Sent from my XT897 using Tapatalk

 

[voidptr]

20mm is to big for 19.5mm
This is what you need
25/32" = 19.8mm

I didn't check this little set I got from my father
I guess 25/32 was pretty useful at many places

 

[voidptr]

The open stock displays in all the stores near me didn't even have a hook for 20mm *shrug* in an case I have the SO one so I'm hopefully set for the rest of my life...
Sent from my XT897 using Tapatalk

same here ... I went to few general tool stores, no 20mm available onsite...
I have to order online they said ...
maybe I will.... from now tho ... problem solved

 

[Jim C.]

I still use 20mm & 25/32" once in a blue moon. But I work on a wide range of equipment dating from the 60's to the present. It bugs me badly when I buy a set of sockets or wrenches without those sizes.

I frequently tinker with older machines and cars, as a result, I'm always on the lookout for wrenches and sockets that are sized in 32nd increments. In particular, those tools that are 15/32" or larger are a "must have" when working pre-1970 USA made stuff. Although there's probably not much of a market for it, I'd like it if a current manufacturer produced a complete set of tools that covered the larger 32nd sizes (15/32", 17/32", 19/32", 21/32", etc., etc.)

Jim C.

 

[rhandwor]

I have a 23mm drain plug on my Kia Sorento and found a 20mm fitting on a Jaguar AC unit.

 

[WhiffySpark]

I have seen 20mm stuff on a few automotive applications. The line nut for the hydraulic cooling fan on some Jeep Grand Cherokees (which you really need a line nut crow foot for ) and the alignment cams on some Audis both require 20mm stuff.

I'm 90% there's a brake caliper bracket bolt that is 20 as well. But I can't remember what it is

 

[n8n]

I frequently tinker with older machines and cars, as a result, I'm always on the lookout for wrenches and sockets that are sized in 32nd increments. In particular, those tools that are 15/32" or larger are a "must have" when working pre-1970 USA made stuff. Although there's probably not much of a market for it, I'd like it if a current manufacturer produced a complete set of tools that covered the larger 32nd sizes (15/32", 17/32", 19/32", 21/32", etc., etc.)

Jim C.

That's been my current thing I'm looking for as well. SK makes 9/32" and 11/32" combo wrenches (the latter IMHO being a must have) but it seems that I'm relying on the pawn shop to find anything bigger. Also why do 3/8" socket sets skip 11/32"?

Sent from my XT897 using Tapatalk

 

[MrNatural]

Found a 20mm nut today securing the drop link on a Fiat Scudo. My Snap On hi-performance 20mm wrench, just lost it’s virginity.

 

[Wrench97]

 

[Flyordie]

Actually I couldn't find a Craftsman 6 point 20mm 3/8"... ended up buying a Snap-On one off eBay. Kinda stupid because it'll likely be the least used socket, but I couldn't abide the missing space on the socket rail.

I have one. lol. Brand new. Haven't used it yet. Have a 12pt version too.

Eesh, this is an old thread.

 

[Jtels85]

My Craftsman G2 3/8” drive metric set goes from 6-22mm, no skips. The only two sockets that I’ve never used which still appear brand new are the 6mm and you guessed it... the 20mm. The 9mm has been used on something before. The 11mm recently lost its virginity on a 10mm belly pan screw underneath my car that got flattened and spread when I bottomed out at an intersection.

 

[Jason280]

The draw bar for tightening collets on my Induma milling machine is 20mm, one of the only times I've ever recall needing a 20mm socket.

 

[lugnut71]

Yes gm fuel filters and some gm engine oil cooler lines at radiator