What wrench to use on the size of bolt

[Zr2guy]

I need to know what the converisions are for what size wrench you would use to remove a bolt by the bolt size not the head of the bolt Like a 1/4inch fine theard bolt what size wrench would you use. This is on a maintance test that I will be taking soon.

Roger

[gubment_cheez]

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[Robert Fogt]

I was not aware that the size of the threads determined the size of the bolt head. But there may be standard sizes. Maybe this chart will help.

http://www.march7.com/databook/bolt.html

[gubment_cheez]

I've noticed that on my computer, I have several bolt shaft sizes, but they all have the same head size. larger shafts hold the cover on the chassis, and smaller ones hold the disk drives in the computer, but the head sizes are the same. additionally, the heads are multi-headed (they have phillips, slotted, and wrench, all on the same head)

[Robert Fogt]

Yes I would have thought that the thread size or shaft size would in no way determine the size of the bolt head. But I wasn't sure.

[Unregistered]

I need to know what the converisions are for what size wrench you would use to remove a bolt by the bolt size not the head of the bolt Like a 1/4inch fine theard bolt what size wrench would you use. This is on a maintance test that I will be taking soon.

Roger
I was just using that as a example the thread course or fine does not make a bit of differance. If you have a 1/4 or 5/16 or 3/8 or 1/2 inch bolt what size wrench or scocket would you need to fit that bolthead?????

Also metric would be nice to know if they have that on the test too.


Roger

[gubment_cheez]

I was just using that as a example the thread course or fine does not make a bit of differance. If you have a 1/4 or 5/16 or 3/8 or 1/2 inch bolt what size wrench or scocket would you need to fit that bolthead?????

Also metric would be nice to know if they have that on the test too.


Rogerif you're referring to the bolt head size, you would need a 1/4 or 5/16 or 3/8 or 1/2 inch socket size. metric sized sockets are measured in millimeters, so you would need to convert from inches to millimeters, to find the size socket you need, (6 mm, 8 mm, 9 mm, and 13 mm, respectively, ceilinged to nearest millimeter, so the sizes aren't an exact fit)

[WolfEyes]

I don't agree. a 1/4 " bolt has a 7/16" head so the wrench size would be
7/16".

[Robert Fogt]

But do all 1/4" bolts have a 7/16" head?

I think thats the problem we are having, no way to tell if there is a standard size head for each shaft size.

Plus I think we are getting the terminology mixed up a bit. Everyone is thinking something different. lol

[gubment_cheez]

I see my attempt at disambiguity has gone unnoticed. I explicitly said "bolt head size" not "bolt shaft size" a bolt itself has different sizes. if you simply say bolt, it is unclear if you're talking about the shaft, or the head.

[WolfEyes]

Here is a chart for metric bolt shaft size to wrench conversion.

http://www.boltdepot.com/fastener-information/Bolts/Metric-Bolt-Head-Size.aspx

Here is a chart for american or sae conversion.

http://www.boltdepot.com/fastener-information/Bolts/US-Bolt-Head-Size.aspx

And yes 1/4'' does have two wrench sizes 7/16'' and 3/8'' .

[Unregistered]

I am more aware of metric fasteners than I am of inch fasteners but I do know that different bolts have different size heads. In the metric world, these characteristics are described per DIN numbers. Every DIN number has different specifications and so when you call out a DIN number to a distributor or manufacturer, you are basically telling them what specifications that you want or need. It is also commom to refere to a bolt's size by the diameter of the shaft and by the length. So a M16 X 40 would have a 16mm diameter on the shaft and it's length would be 40mm.

I call Eurolink FSS when I'm in need of metric fasteners. They used to be known as Supply-Line Fasteners, but they changed their name recently.

[TOD f]

THE SIZE OF THE HEAD IS ALSO DET. BY IF THE BOLT IS FINISHED(STANDARD )i.E 1/4" BOLT USE 7/16" WRENCH, OR Heavy head 1/4 inch bolt FOR USE W/ 1/2" WRENCH HEAD.

[Unregistered]

1.5 X diameter of bolt = wrench size
add 1/8 for hard bolts.

[Unregistered]

this is your save all. multiply the bold diameter by 1.5 that will give you the head of your bolt. If useing extra heavy nuts add 1/8th to your wrench size.

[Unregistered]

1.5 x Bolt Shank Dia. = Hex Head/Wrench Size. Add 1/8" (.125) for Hard Bolts.
(SAE only. formula does not work for metric.)

Also to find what size hole the BOLT HEAD will fit through (such as use with a keyhole slot) the formula is Width Across Corners = Width Across Flats/cos(30deg)

and Width Across Corners = 2xLength of Hexagon Side

Hope that is useful

[Unregistered]

Good greif! all this talk about shaft sizes when the head size was specifically asked for, I had the same problem at 4 hardware stores when I called to ask for them to measure a botlt HEAD size for me, it was resolved when I drove 16 miles and did it myself. America is in big trouble folks!

[JohnS]

Good greif! all this talk about shaft sizes when the head size was specifically asked for, I had the same problem at 4 hardware stores when I called to ask for them to measure a botlt HEAD size for me, it was resolved when I drove 16 miles and did it myself. America is in big trouble folks!

And contrary to all the above, there is NOT a guarenteed dimension across the flats given bolt diameter. Several high volume industries specify custom fasteners that use a small number of head sizes to minimize the number of wrenches required, and apply those heads to a range of bolt diameters.

There may be a "usual" head size, but it is not so universal to be deserving of being called a standard. Use the wrench that fits. For non-critical tightening, use an adjustable wrench (Crescent®)

[Unregistered]

1/4 is 7/16--5/16 is 1/2--3/8 is9/16--7/16 is 5/8--1/2 is 3/4 Generally

[Unregistered]

What size hammer wrench do I use for a 7/16 5K flange?

[JohnS]

What size hammer wrench do I use for a 7/16 5K flange?

If the bolt head is 7/16 across the flats, 7/16.
If 7/16 is the bolt diameter, measure the head across the flats, that's the wrench size.

There is supposed to be a standard for head vs diameter, but it is not always followed. Use the wrench that fits.

[Unregistered]

multiply the size of bolt by 3/2. IE, a 5/8 shaft by 3/2. 5/8 x 3/2= 15/16

[Unregistered]

For metric wrench size--- simply double the (metric) size of the bolt and then add 1mm e.g 5mm bolt requires 2x5+1mm wrench + 1mm wrench