UNC UNF BSW Metric

[bazz]

Since i am living in a metric system part of the world i'm getting enormously confused with all these thread sizes.

I want to buy a large set of english thread dies and taps but have to choose whether i buy a large one containing

everything i need in UNC/UNF or one in BSW/BSF.

I have a series 3 109 safari landrover build in 1977. Which should be the best choice for me (providing nothing got mixed up earlier)

thanks

Bas

[rtbarton]

Broadly speaking UNF are used on the engine, UNC & UNF where the gearbox and engine meet. UNF or sometimes Metric on the body/chassis and BSF & UNF on the axles.

[Les Henson]

Aren't the two 7/16" head bolts that hold the gearstick bracket to the bellhousing Whitworth?

Les.

[bill van snorkle]

The gearbox/transfercase on series Landrovers are held together with 5/16, 3/8 and 7/16 BS nuts and bolts. The swivel housings and stub axles by 3/8 BS. Propshafts, differental banjo, gearbox to flywheel housing 9/16'' SAE (unf). Pinion nut,(Rover type) transfercase output shaft castle nuts 1''. SAE. Salisbury diff pinion nut 1 1/4'' SAE . 2 1/4 litre engines are SAE, 2.6 litre 6 cyl engines are BS. Body work mainly 7/16 and 1/2'' SAE. AFAIK no other manufacturer would build a vehicle with BS,SAE and Metric fastenings, but LandRover did with the Stage one V8 series. I wrote SAE and BS rather than UNF and Whitworth because spanners and sockets for UNF (fine thread) and UNC (coarse thread) are determined by the bolt/nut head dimension, whereas for BSW (coarse thread) and BSF (fine thread) it is determined by the diameter of the bolt shank.

Bill.

Edit, I just checked a couple of old sockets i have. One is a 5/16'' BS that is also marked 1/4'' whitworth, the other is marked 3/8'' BS and 5/16'' Whitworth. I don't know what that is all about. I can only assume that very early Whitworth fastenings had larger hex diameters than later on, but this practice would certainly pre date LandRovers anyway.

[rtbarton]

Edit, I just checked a couple of old sockets i have. One is a 5/16'' BS that is also marked 1/4'' whitworth, the other is marked 3/8'' BS and 5/16'' Whitworth. I don't know what that is all about. I can only assume that very early Whitworth fastenings had larger hex diameters than later on, but this practice would certainly pre date LandRovers anyway.

They did and not only on older fasteners.

AFAIK larger heads were always fitted to BSW screws, although I've seen the smaller heads on BSW screws too.

[bazz]

The gearbox/transfercase on series Landrovers are held together with 5/16, 3/8 and 7/16 BS nuts and bolts. The swivel housings and stub axles by 3/8 BS. Propshafts, differental banjo, gearbox to flywheel housing 9/16'' SAE (unf). Pinion nut,(Rover type) transfercase output shaft castle nuts 1''. SAE. Salisbury diff pinion nut 1 1/4'' SAE . 2 1/4 litre engines are SAE, 2.6 litre 6 cyl engines are BS. Body work mainly 7/16 and 1/2'' SAE. AFAIK no other manufacturer would build a vehicle with BS,SAE and Metric fastenings, but LandRover did with the Stage one V8 series. I wrote SAE and BS rather than UNF and Whitworth because spanners and sockets for UNF (fine thread) and UNC (coarse thread) are determined by the bolt/nut head dimension, whereas for BSW (coarse thread) and BSF (fine thread) it is determined by the diameter of the bolt shank.

Bill.

Edit, I just checked a couple of old sockets i have. One is a 5/16'' BS that is also marked 1/4'' whitworth, the other is marked 3/8'' BS and 5/16'' Whitworth. I don't know what that is all about. I can only assume that very early Whitworth fastenings had larger hex diameters than later on, but this practice would certainly pre date LandRovers anyway.

Okay,

so to clean (or rethread) threads on the technical part (engine, gearbox, etc) it is mainly BS but some SAE, bodywork is UNC/UNF. Basicly i need a UNC/UNF and a BSW/BSF set of dies and taps. Unbolting everything went fine with a mostly metric toolset. I'll start looking for imperial sizes for those as well.

thanks again.

Bas

[Paul Humphries]

Since i am living in a metric system part of the world i'm getting enormously confused with all these thread sizes.

I want to buy a large set of english thread dies and taps but have to choose whether i buy a large one containing

everything i need in UNC/UNF or one in BSW/BSF.

I have a series 3 109 safari landrover build in 1977. Which should be the best choice for me (providing nothing got mixed up earlier)

thanks

Bas

I wouldn't buy a set but rather "cherry pick" just the sizes you need.

A full set will have loads that you will never, ever, use so why waste money.

It might be worth investing in a thread gauge to determine what you need.

Personally I am interested in hobby engineering and taps / dies are cheap from shows / mail order.

Obviously not 100% best industrial quality but certainly no worse than you would get in a set and more than adequate for DIY use.

Have a look here -

http://www.chronos.ltd.uk/

http://www.tracytools.com/

I also find a thread file useful for tidying slightly damaged threads-

http://www.justoffbase.co.uk/core/media/me...e7afa6c9b14fbe6

Paul Humphries

[bill van snorkle]

Okay,

so to clean (or rethread) threads on the technical part (engine, gearbox, etc) it is mainly BS but some SAE, bodywork is UNC/UNF. Basicly i need a UNC/UNF and a BSW/BSF set of dies and taps. Unbolting everything went fine with a mostly metric toolset. I'll start looking for imperial sizes for those as well.

thanks again.

Bas

The only UNC threads on series LandRovers I can think of are on studs where they screw into alloy castings. There are few if any actual bolts and nuts for body or mechnical that have a UNC thread, but a tap and die kit covering BSF/BSW and UNF/UNC will cover most threads on the vehicle wth the exception of wheel studs(metric) and transfercase output shaft/diff pinion threads (mongrel thread ?)

Bill.

Edit, Myfirst post stated that the gearbox/transfercase fastenings were 5/16'', 3/8'' and 7/16'' BS. There are also 1/4'' BS bolts and studs that attach the t/case bottom access plate, gearbox selector detents etc, and as Les earlier mentioned, the two front bolts that attach the gear lever mounting to the bell housing.

[FridgeFreezer]

I would cherry pick as you need them, check out Tap & Die Co who I have bought a few things from on the recommendation of other forumers - a very good service and the stuff they sell is good (industrial) quality.

I have used some "hobby" quality tap & die kits before and they really are bad compared to the proper stuff - produce a poor thread and seem to make it far easier to muck it up - not what you want if you're doing threads in the engine or gearbox.

[Les Henson]

A lot of metric sizes are near enough to imperials.

11mm = 7/16"

13mm = 1/2"

14mm = 9/16"

16mm = 5/8"

19mm = 3/4"

25mm = 1"

If you have a very rusty metric nut or bolt, then it's handy to have an imperial set of sockets to knock on - 3/8" is a good tight fit on a damaged 10mm for example.

Les.

[bazz]

A lot of metric sizes are near enough to imperials.

11mm = 7/16"

13mm = 1/2"

14mm = 9/16"

16mm = 5/8"

19mm = 3/4"

25mm = 1"

If you have a very rusty metric nut or bolt, then it's handy to have an imperial set of sockets to knock on - 3/8" is a good tight fit on a damaged 10mm for example.

Les.

Yes, i noticed that. loosening or fastening hasn't really been a problem. I only had to resolve to the grinding disc with the nuts and bolts that held the small panel behind the seatbase. It is with cleaning threads that it is really confusing to me which thread system i need.

I ordered a BSW, BSF set and a UNF (taper and bottom, dies) set to start. Where needed (after i got some experience with these sizes) i'll get industrial quality stuff of the sizes i really need.

thanks everybody!!

strange though that the green book only talks about metric and unf bolts. Did they just build these things with whatever they had availlable at the production line? surely they were not planned to be build with all these sizes mixed together, what would be the benefit of that except keeping people busy.

[rtbarton]

strange though that the green book only talks about metric and unf bolts. Did they just build these things with whatever they had availlable at the production line? surely they were not planned to be build with all these sizes mixed together, what would be the benefit of that except keeping people busy.

It's historical development really. In 1948 (?) when landrovers came out BSF/Whit were the only threads used on British cars. In the 60s UNF/UNC was introduced, especially by American based manufacturers, but to avoid re-tooling BSF was retained on items that had tapped threads in them (Axle ends, bellhousings &c) whereas UNF could be used for nuts & bolts. Metric came in in the 80's and used on the 5 bearing engines which were effectively new design anyway.

Personally I would used metric wherever possible for nut & bolting as the coarser thread is likely to seize up.

[FridgeFreezer]

If you're rebuilding the vehicle, buy a party-sized assortment of metric nuts & bolts and replace as much as possible with those.