Bolt dimensions relationship

[lillidelft]

Hi everybody,
first time posting here

Does any of you know if it exists an analytical relationship between the dimensions of a standard steel bolt?

E.g. a relationship between the bolt head diameter and the shank diameter...or between the length of the shank and the thickness of the bolt head

 

[CoryPad]

Yes, these relationships exist. For each family of products (hexagon head, hexagon flange head, pan head, etc.) there is a relationship between head outer diameter and the shank diameter and the thread major diameter and the head height, among other dimensions.

 

[rb1957]

if you want general rules ... the head dia. is twice the shank; head height is not related to grip length (it's fixed at about a shank dia.)

if you want specifics, look up a bolt MS on the ASSIST website.

 

[KENAT]

What do you mean by standard steel bolt?

Hex head?

rb1957s rule is very approximate and doesn't apply to all head types. I had a mystery bolt just the other day 10MM across the hex head. Looked it up on-line (plenty of tables out there, just google) and it was an M6. For most series of bolts there is an approximate mathematical relationship, but the values are often then grossly rounded to get a nice round number (and limit the amount of tool sizes required).

Like the others say, there isn't generally a relationship between head height & nominal thread dia. For some head forms/fastener types there may be low profile options but generally it's the same head height regardless of length.

A resource like Machineries Handbook should allow you to look up the actual values for most common types.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[lillidelft]

KENAT: Hex Head, 6 mm diameter, class 8.8

About the rb1957 suggestion, I have already noticed I cannot simply take the double of the shank diameter. I have also evaluated the ratio between the head and the shank diameters, and their difference. Nothing remains constant.

I am looking in the ASSIST website, to look for more info.

CoryPad: any references?

Thank you all!!!

 

[KENAT]

Well, mine was I think an 8.9 but it was M6 with 10mm head.

In case I wasn't clear before you need to look it up. Preferably in the relevant standard, else machineries probably has it, else search the web.

http://euler9.tripod.com/bolt-database/

is the first thing that turned up with a google search.

There are also various specials, some of which may be to some kind of standard, some which may not.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[CoryPad]

ISO 4014 for hexagon head
ISO 4162 for hexagon flange head
ISO 4762 for heaxagon socket head

etc.