Which screw thread gage to get?

[Putt-Rite]

I'm cannibalizing lawn mowers for Al and all the screws etc. I want to get a screw gage and want to know which one is the correct one?

I'll be reusing the screws for builds and need to know what their pitch is for the taps and drills. The engines are Briggs and Tecumseh and take mostly American wrenches except for a rogue 18mm or 19mm which might be an American screw but the metric wrench fits.

Thanks you guys are awesome

 

[Putt-Rite]

Like how about this one? I'm getting the Porter book on propane burners, and would get free shipping if I placed a $25 order.


http://www.amazon.com/dp/B004ROIU2A/?tag=skimlinks_replacement-20

 

[Putt-Rite]

Now I'm confussed.

Am I reading this right, there is a 55 deg and 60 deg American, a 55 deg Whitworth, and a metric standard?

 

[Swifty]

Whitworth and BSP pipe threads are 55deg, unified (unf, unc), NPT pipe threads and metric threads are 60deg.

Paul.

 

[Tin Falcon]

That thread gage should work fine just remeber you need to measure diameter as well be careful because some sae and metric sizes can be close.
1/2 in is 12.7 mm a 1/2 in wrench may or may not fit on a 13 mm bolt head.

the other option is get a thread checker of bolt detective. a series of male and female gauges to try the bolt in.but at 25 -70 usd you may not have the extra.
Tin

 

[tornitore45]

Thread gages is inexpensive and it pays to have both Imperial and Metric

However, if you are the kind of guy that has at least a box with all sorts of nuts and bolts, or even better a multitude of size labeled jars then a thread checker is not indispensible.

Just find the nut that fits the bolt and then the tap that fits the nut.
No charts? Find the drill bit that fits the nut and you are very close to the core bit.

In a pinch can use the tap to match a thread assuming you already have an assortment.

Most folks in the machining business/hobby can ID the most common threads by eye.

 

[chucketn]

Fastenal and most fastener distributors sell a plastic gage with holes for screw sizes and pins for nut sizes. Handy to have.

Chuck

 

[Alchymist]

http://www.boltdepot.com/fastener-information/Printable-Tools/Default.aspx

http://www.boltdepot.com/Thread_gauges.aspx?nv=l

 

[MCRIPPPer]

the nice thing about bolts is that there are only a few different threads in each diameter. and most of them are very rare, so there are only a few different sizes you will commonly find. (unlike drill bits... can you tell the difference between a 1/4 inch and an E ???!!!???) you will be able to identify bolts after a while. i keep all metric taps and dies and bolts. i only have imperial bolts from stuff i take apart. metric is the way to go imo!

 

[Lakc]

the nice thing about bolts is that there are only a few different threads in each diameter. and most of them are very rare, so there are only a few different sizes you will commonly find. (unlike drill bits... can you tell the difference between a 1/4 inch and an E ???!!!???) you will be able to identify bolts after a while. i keep all metric taps and dies and bolts. i only have imperial bolts from stuff i take apart. metric is the way to go imo!

Brought back wonderful memories of my neighbor and best mans grandmother, she worked at Whitman and Barnes back in the day, sorting drill bits. She could tell a 1/4 from and E by feel. I think he still has some of his grandparents drills laying around.

 

[MCRIPPPer]

i had to refill the drill indexes at work and find all the ones people throw into the "drill bit drawer". drill bits are the worst because there are so many, thay start to overlap! an E is 1/4 inch!!!!!! lol.

drill indexes have too many drill bits in them!

 

[dnalot]

I just bought this one

http://www.amazon.com/gp/product/B003FJW0GK/?tag=skimlinks_replacement-20

It identifies both male and female threads (metric also available) Works great

Mark T

 

[OrangeAlpine]

There really is no metric standard thread. The "standard" simply states the thread description shall be in metric terms.

Bill

 

[tornitore45]

can you tell the difference between a 1/4 inch and an E

My chart say E=0.250 which is strange because splitting the difference between a D=0.246 and F=0.257 would give ~0.252 as a good candidate for an E without creating two identical sizes with different name.

So what is the difference between a 1/4 and E according to Lakc's charts?

 

[MCRIPPPer]

the chart i have has e and 1/4 in the same line which says .25

 

[MCRIPPPer]

There really is no metric standard thread. The "standard" simply states the thread description shall be in metric terms.

Bill

well every 5mm bolt i see is m5x.8, all 6mm i have seen are m6x1, all the 4mm bolts i see are m4 x.7. the larger sizes have a few options like m10x 1 or m10x1.5.

 

[OrangeAlpine]

well every 5mm bolt i see is m5x.8, all 6mm i have seen are m6x1, all the 4mm bolts i see are m4 x.7. the larger sizes have a few options like m10x 1 or m10x1.5.

Might be, but the Wikipedia list of Metric thread sizes lists them as "Preferred Sizes". The ASME threads are listed as "Sizes".

Bill

 

[goldstar31]

well every 5mm bolt i see is m5x.8, all 6mm i have seen are m6x1, all the 4mm bolts i see are m4 x.7. the larger sizes have a few options like m10x 1 or m10x1.5.

Somehow, I think that you should ask a better source of information.

I sit with an old copy of Machinery Handbook. It was published in 1940-ish when the Americans had 'doubts' about us Brits. I doubt that it is really comprehensive but it is a good starting point.

And- Oh dear- plastic gauges. Really, I also have my doubts.

Regards

Norman

 

[pete]

There really is no metric standard thread. The "standard" simply states the thread description shall be in metric terms.

Bill

WTF.........................????????????????
No standards for metric threads? Unless I'm reading or at least failing to somehow understand your point as completely and totally wrong? I'm sure as hell lost on your statement and how it could be even close to correct. That's like saying the earth is friggen flat.

Even the U.S. military uses metric and has for a very long time. I'd very much hate to think the $60.00 + I spent on a set of half decent metric Mitutoyo thread gauges for those somewhat 'standard' metric threads was an actual waste. There's also hardened and ground and very high precision low tolerance male and female thread gauges worth hundreds to over thousands of dollars depending on the the exact thread tolerance required that might prove different than what your saying. About any large machine tool supplier carry's them if it's needed for commercial purposes. You can even buy or order specialty thread gauges including metric in any + or - specification you'd care to name and far past what 99.999999% of us can do. So I dunno, wot the hell do you know that I've and the rest of the world have somehow missed?

Thread standards including metric were decided on a very long time ago by far more intelligent people than us. I'd sure like to see exactly where those metric threads have no standards, yet imperial somehow does?

And to be honest? I'm anti metric, I happen to think in imperial. Yet I'll still admit the metric system is a far superior measurement system.

IMO? The moderators on this forum should be correcting this type of misinformation long before it gets to be this type of misinformation.

Pete

 

[Tin Falcon]

IMO? The moderators on this forum should be correcting this type of misinformation long before it gets to be this type of misinformation.

First of all Pete tone it down and calm down. your last two posts have been bashing others opinions and language on the borderline of vulgar .Remember respect. Calm down tone it down or be banned for 7 days to cool off.

There really is no metric standard thread. The "standard" simply states the thread description shall be in metric terms.

Bill

IMHO you statement should have had an IMHO in front of it.
Of course there are standard sizes or the world be mayhem like in the early days of machining and industry when every shop made the size of fastener and thread pitch to there liking.
that is why we have thread charts pitch gages etc. to conform to the standard. Every common thread has a go no-go gage to determine if it is within the specification for that size.
I think part of the problem is to folks comfortable with SAE standards metric seems random with thread pitch. And SAE id definitely perceived as random to the metric folks.

So the spirit of this thread is to help this young eager apprentice classify and identify and sort threaded fasteners.

The metric vs SAE debate has been discussed before.
so please lets try to stay focused on the intent of the thread. encourage learning and respect others points of view.
Tin