DIN 41612

DIN 41612 is a standard for connectors that are widely used in rack systems

A connector can have one, two or three rows of contacts, which are labelled as rows a, b and c. Two row connectors may use rows a+b or rows a+c. The connectors may have 16 or 32 columns, which means that the possible permutations allow 16, 32, 48, 64 or 96 contacts. The rows and columns are on a 0.1 inch (2.54 mm) grid pitch. [ref wikipedia]. Connectors can also be straight or right-angled. 

Manufactures offer many different types of 41612 which can make finding a socket and plug combination that match frustrating on the big electronic parts websites.

I eventually found the following 64 way, a+b, 2.54mm, B shell sockets and plugs at toby.co.uk which appear great value.

Part No	Quantity	Price
B shell 2 row sockets
405AF-64FSSAAB4	10	£9.50
B shell 2 row plugs
405AF-64MSRAAE4	10	£7.50

The data sheet gave the following physical sizing for the right angled B shell plugs

• Distance between screw centres = 88.90 (~3.5 inch)
• Length = 94mm (~3.7 inch)

and the following for the vertical B shell sockets

•  Distance between screw centre = 90mm (~5.55 inch)
• Length = 95 mm (~3.7 inch)

Looking at the EagleCAD parts library I found the part MAB64 in the con-vg library which seems to match the plug and MAB64Q the socket therefore I have gone ahead and order 10 of each.