Official Luthiers Forum!

hi i just wanted to know what size the inserts size is on a bolt on neck
ive decided to convert all my dowel neck cheapies and have two necks off
and need to get bolts and inserts
i have a copy of lmi on front of me and im looking at the bolts
the discription of the inserts is wrote down as follows
brass 1/2 inch long
1/4 "ID ., 7/16 "OD
what does ID and OD mean ?
or can someone please just write down the size of them
in a different text........ thanks in advance
tomas

ID is the size of the bolt, so the 1/4 means a 1/4" bolt, usually a 1/4" with 20 threads per inch or a 1/4-20.

The OD is 7/16" that means the mean thread size is 7/16"

To get a good bite into the wood you'll want a self threading insert. That means it'll cut into the wood as you turn it into place. Otherwise they kind of just mash themselves into place and don't really bite into the wood when they seat in.

ID = inside diameter
OD = outside diameter

_________________
Cut to size.....Beat to fit.....Paint to match.

sorry i didnt explain myself well their atall but im still on the net looking for the right inserts
and i think their measured differently
could anyone tell me if any of these are the right ones ?
2-56 brass threaded insert or
4-40 6-32 8-32 10-32 i should have wrote that in too
or if their all wrong wheres the best place to get them thanks

You can get these inserts at lowes and Home depot. You should use the brass threaded insert that look like these
http://cgi.ebay.com/178-4-Brass-Threade ... .m20.l1116
The slotted end goes into the hole first . They are a bit trickie to set ,I use a shoulder bolt to seat the insert to the hole. They are plenty strong and these are like the ones Martin uses and they only use 1 on a neckk
john hall

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

The LMII set comes with the inserts - you don't need to buy anything else.

--Steve

_________________
---Steve

This might be of help, as it will give the screw numbers meaning for you.
Unified Thread Standard

The United States of America has its own system, usually called the Unified Thread Standard, which is also extensively used in Canada and in most other countries around the world. At least 85% of the world's fasteners are dimensioned to Unified thread dimensions, and the biggest selection of fastener sizes and materials are found supplied in this standard.[20] A version of this standard, called SAE for the Society of Automotive Engineers, was used in the American automobile industry. The SAE is still associated with inch-based fasteners by the public, even though the U.S. auto industry (and other heavy industries relying on SAE) have gradually converted to ISO preferred series fasteners for some assemblies from the 1970s onward, because global parts sourcing and product marketing favor international standardization. However, all automobiles sold throughout the world contain both metric (engine assemblies) and Imperial fasteners (for example, lug nuts, oxygen sensors, internal electrical assemblies, body fasteners, lamps, steering, brake and suspension parts).

Machine screws are described as 0-80, 2-56, 3-48, 4-40, 5-40, 6-32, 8-32, 10-32, 10-24, etc. up to size 16. The first number can be translated to a diameter using a formula, the second is the number of threads per inch. There is a coarse thread and a fine thread for each size, the fine thread being preferred in thin materials or when slightly greater strength is desired.

The numbering system follows a roughly logarithmic series where an increase in each screw number size approximately doubles the tensile strength of the screw and the screw number is found by d=.060''+(\# \times .013''), where "d" is the nominal diameter. Using this formula a #5 screw has a major diameter of .125" (1/8"), a #10 screw has a diameter of .190" (or 3/16" in practical terms), etc. The formula applies for screw thread numbers #0 and higher, but does NOT apply to smaller Unified miniature screw thread series. Typically screws smaller than size #0 are supplied in the Unified Miniature Series. The formula for number sizes smaller than size #0 is given by d=.060''- (\#zerosize \times .013), with the zero size being the number of zeros after the first. So a #00 screw is .047" dia, #000 is .034" dia, etc.

The number series of machine screws once included odd numbers (7, 9, etc.) and extended up to #16 or more. Standardization efforts in the late 19th and the early part of the 20th century reduced the range of sizes considerably. Now, it is less common to see machine screws larger than #14, or odd number sizes other than #1, #3 and #5. Even though #14 and #16 screws are still available, they are not as common as sizes #0 through #12.

Sizes 1/4" diameter and larger are designated as 1/4"-20, 1/4"-28, etc. the first number giving the diameter in inches and the second number being threads per inch. Most thread sizes are available in UNC or UC (Unified Coarse Thread, example 1/4"-20) or UNF or UF (Unified Fine Thread, example 1/4"-28).

A Unified Miniature screw thread series is defined in ANSI standard B1.10, for fasteners of 0.3 to 1.4 millimetres (0.0118 to 0.0551 inch) diameter. These sizes are intended for watches, instruments, and miniature mechanisms and are interchangeable with threads made to ISO Standard 68.[21]

_________________
Dean

Have you considered using 1/4-20 hangerbolts?

_________________
https://soundcloud.com/jeffreylsuits/he ... -runnin-13

thanks so much guys finally got the right ones
if anyone in the EUROPIAN UNION is looking for them i found them on ebay
theirs packs of 30 for about 15 euros inc postage cost

30 threaded 1/4-20 brass woodworking inserts

hoping to get the allen bolts locally
thanks again guys and sorry to the pros
for clogging your page up
tomas

Tomas;
www.mcfeeleys.com has steel inserts with deepthreads.
they are much better than the brass ones !
Same inside thread.
If you have trouble getting them -P.M. me & I'll send ya some !!

Michael Collins!!

_________________
Mike Collins

thanks alot for the offer ive allready bought them
but its only cheapies im workin on for now
a good tip anyway for when im finally making some
thanks again tomas

I use the 1/4-20 knockdown bolts and threaded inserts from Woodcraft.
http://www.woodcraft.com/family.aspx?FamilyID=1045
http://www.woodcraft.com/product.aspx?P ... ilyID=1048

Justin