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Basic E-Type Question: Fasteners - Metric or SAE or ...?

VooDooDaddy63

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As I mentioned in my introductory post, I’m probing around the edges of a 1970 Series II E-Type trying to ascertain the damage.

I replaced the gear shift knob recently and discovered that it had a 5/16” 18 threaded connection.

However, the seat fasteners seem to be:
  • Floor Mounts: 6mm x 1.25
  • Seat Position Assembly: 6mm x 0.9

I have a small assortment of metric taps and dies, but nothing with these thread counts.

Am I measuring this correctly?

As I dig into this project, will I be needing to build up a selection of non-metric taps and dies?

I want to clean up and salvage old fasteners, before making a bulk order to replace the most-damaged ones.

Answers to these questions will help me get the right mindset (and tool set) for this project. :rapture:
 
I have restored 1969 and 1970 e types in the past and do not recall any metric. Be sure that someone previously hasn’t botched it.
 
I believe the seat to floor fasteners are 7/16 NF. Always nice to have a book...I only purchase Bentley or factory editions.
 
I believe the seat to floor fasteners are 7/16 NF.

My floor fasteners are M6 x 125. So, I'm thinking that the old ones rusted out and they refitted it with metric fasteners.

Always nice to have a book...I only purchase Bentley or factory editions.

I learned recently that Jaguar did not issue a comprehensive parts list for the E-Type Series II. So, the author researched all of the available information on that edition's parts and published this book.
 
Mystery Solved!

These bolts were BSF and BSC threads. (Basically, fractional inches.)

Once I got a good fractional gauge, I was able to get the following measurements.
- Floor Mounts: 1/4” x 20
- Seat Position Assembly: 1/4” x 28 (Hard to find!)
 
My DIY hardware store carries these bolts, seems they decided to go with the area and even bought a complete cabinet full of specialized gun screws.
 
Bolts Bolts Bolts Standard Course and fine thread that's it But they do have grads see top of bolt 3 5 8 and marking are 3 blank 5 slashes 8 triangle replace with same grad. 3 we called butter bolts weak zero work load 5 for working load and torque load 8 strength head bolts one time use after torque. I use SS bolts where rust happens but not load seat frames mounting acc. under hood for looks. As for the nuts that can also apply but not much in cars. Bolts do two things tie things together torque things down nut hold bolts. The weakest point of a bolt threads so less threads the better say any front end parts. Fine thread bolts may have a different torque than course may also if in say block as to through bolting.

Metric different numbers thread count and head size UK did not go to Metric but early Wentworth say MG T's had same bolt threads bigger head size EU cars use Metric bolts with even number wrenches Jap odd number wrenches or the other way around. So to end many taps many wrenches mine are painted different colors. Madflyer
 
My 94 XJS had bot metric and SAE threaded fasteners.
While I was working at an Independent Jaguar, Bentley and Rolls Royce shop,
I took home every fastener that was going to the trash.
Now, I have a tool chest filled with spares and no vehicle for them.
Let me know if I can help out.
I need to supplement my SSI to survive.
 
Geez, just read what I posted and it should have been 1/4 nsf not 7/16. That would be one large fastener of a seat!
I must read before posting.
glad you have a book now.
 
Whitworth, British National Fine thread, or SAE. Use adjustable over metric. Wasn't metrics in the era of E-types. Once you round a bolt, it stays rounded.
 
No metric fasteners on any E-Type.

Practically all the fasteners on an E-Type are Unified Series which is virtually the same as SAE, so they're mostly UNF or UNC.
Early E-Types have some BSW and BSF on items like the Moss box which were carried over from earlier models. There may also be some B.A. (British Association) for small screws on items like the carburettors and some older Lucas stuff.
Pipe threads are likely to be British rather than American NPT.
 
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