Definitive thread on XK120 DHC floor screws

Ok. I saw a GREAT photo of an OTS floorboard set with the screws laid where they go. I want this for my DHC, but I have not been able to find one, so I thought I would make one. I do not, however have any idea whats what. Oddly, everything on my car was basically left alone EXCEPT the floor screws lol.

I found in my car as I dismantled it a few different styles:
round head, pointy tip (small length and long length)
Round head, float tip (both sizes)
Flat countersunk tip with:
pointy tip (only seem to have one length on this one- long)
flat tip
three sizes- small medium and long.

I need to understand:

  1. where each of these go
  2. how many of each

As soon as I have gathered this information, and once I have acquired the missing bolts, I will lay out the floorboards and take a nice clear picture so we will have a definitive reference.

If anyone is holding, and wants to pass them to me for science, I will be forever grateful.

I began this drawing and fastener list back in January, finally finished.

Drawing key, list of fasteners as pdf.

XK120 FHC-DHC floor fasteners.pdf (42.3 KB)

As always, subject to revision as new information comes to light.

WOW. Thank you. Hopefully it helps the others who tread this path.

I created a quick reference guide * for JUST the screws* to go with your drawing/list: EDITED to reflect corrections

Letter Type Description Langth Total needed Location
B BD1493/1 Round head point tip .5in 4 Trans Tunnel side
A,B,F,G,H BD1493/2 Round head pointed tip .75in 28 Floor frame firewall, Trans Tunnel, Floor frame rear firewall, Prop cover rear firewall, Prop cover to floor frame
BD1493/3 Round head pointed tip 1in 12 boot floor
D BD1494/5 Countersunk head pointed tip 1in 18 Wood floor
E BD1494/6 Countersunk head pointed tip 1.25in 10 Floor frame door edge
J FS404/6h Round head .75in 4 Prop tunnel front
F504/4h Countersunk head flat 1/2in lower seat to runners
L F504/5h Countersunk head flat 5/8in 8 Seat rail tapped bar
L F504/8h Countersunk head flat 1in 8 Seat rail runner through packing and floor

Good to get a check of my typing.

BD1493/3 is a round head, (12) used on the boot (trunk) floor boards with the BD1711 rectangular pinch clips (16). The other 4 were FS404/6H round heads 3/4" long.

FS404/6H is a round head, not flat.

FS504/4H is 1/2" long and secures the lower seat frame to the seat rail runners.

FS504/5H is 5/8" long and secures the tapped bar on the underside of the floor to the floor panel.

FS504/8H is 1" long and secures the seat rail runner through the 3/8" packing and floor panel to the tapped bar underneath.

My guess on the Jaguar’s nomenclature for standard hardware is that FS means Fine Screw, or British Standard Fine BSF. The 3 numbers after FS were assigned to mean various types of screw. The last of the 3 is the diameter in 1/16" increments, i.e. 404 is a round head 4/16" or 1/4" diameter, and 504 is a 4/16" or 1/4" flat head. The number after the slash / is the length in 1/8" increments. The suffix letter is either a strength designation or some other characteristic.

BD means Body. BD numbers were assigned to screws with some special characteristic such as pointed end. 1493 is all 1/4" round heads and 1494 is all 1/4" flat heads. The number after the slash / was just a series number that increased with the length.

Flat head and Countersunk head mean the same thing, just two commonly used names, and the length is measured INCLUDING the head.

Round heads are always measured UNDER the head.

Thanks Rob- In a VERY short time this thread is really packing some great info. I am missing about 38 screws, wish me luck in finding!