Land Rover Fasteners, Screws, Bolts & Washers

Ever wondered what the difference is between BH604161L & BH604151L when sourcing parts for your Land Rover? Well you are not alone. I came across this table on  http://ep90.com which was recommended by FridgeFreezer on the LR4x4 forum

Part Type Thread Size Length Finish Unknown
BT = Bolt 6 = UNF In 16ths of an inch for imperial sizes. x 1/8 inch for imperial. 0 = Bare or Natural
BX = Bolt (H.T.) 5 = UNC

Reads directly for metric sizes (e.g. 06 = M6)

x 1mm for metric, except Bolts are x5mm

 1 = Zinc Passivated
SX = Screw (H.T.)

4 = Whitworth

2 = Nickel / Chrome (external use)
SH = Screw

1 = Metric

 3 = Nickel Chrome (internal use)
FS = Screw, Flange Head 4 = Black (internal use)
WL = Washer, Spring 5 = Black (external use)
WA = Washer, Plain 6 = Black Phosphate for controlled torque
WC = Washer, Plain 7 = Zinc (severe environment)
WM = Washer, Spring 8 = Black stainless
NT = Nut, Thin
NH = Nut, Hex
FN = Nut, Flanged
NZ = Nut, Nyloc
FX = Nut, Flanged
 FX Details unknown – Jam Nut for Exhausts?, Metric??
NY = Nut, Nyloc, Flanged?
TE = Stud, Threaded, UNF at one end.
 TE5 are UNC/UNF, TE6 are UNF/UNF, TE1 unknown
TD = Stud, Threaded
 TD Details unknown, works with FX nuts

So from this, BH604161L can be decoded as:

BH = Bolt
6 = UNF
04 = 4/16ths of an inch = 1/4″
16 = 1/8ths of an inch = 2″ long
1 = Zinc Passivated