Oh... so 1/4" BSP is 1/2" across, then...!

[rtbcomp]

^^ True, but there are exceptions that prove every rule.

I recently bought a SIP compressor, made in Italy, the threads on the feet were standard metric, but none of my spanners would fit the heads, and I have a large range of AF, BSW/BSF and Metric sizes.

 

[normspanners]

It's the current system of labelling spanners with the AF (Across Flats) dimension that's confusing, you have to remember that a 13mm spanner is needed for an 8mm bolt &c.

13mm spanner is needed for an 8mm bolt &c.

or 10 - 12 - 12.3 as I found the other day or 13mm and some 14mm
and now on vehicles a 10mm bolt used to be 17mm standard----------- can be 14-15-16 or 17mm

 

[normspanners]

What really annoys me are front engine mounts on some cars they are usually about 8 ish number of bolts, when doing timing belts, they usually are 10 or 12mm bolts and then nuts on some through bolts etc, holding them, but you can have half your tool box out just to get those same size bolts out.
It is because the engine manuf uses one standard maybe torx the car manuf uses another for the mounts then the body designer uses another, then 12mm nuts could be 18 or 19 depending how they feel.

 

[premmington]

Wheel nuts.

15mm Hex Smartcars (15mm impact socket ground down with tape wrapped round as not to mark alloy wheels)

22mm Hex Land Rover Discovery-Freelander, BMW X5



Cylinder head bolts.

Ribe M9 Fiat, VAG

Ribe M10 x 140mm VAG 1.8-2.0 V6

Ribe M12 x 120mm Fiat

Ribe M13 x 100mm Alfa, Fiat Lancia

Ribe M14 Fiat

Spline M9 Toyota

Spline M10 x 140mm Mercedes Sprinter

Spline M12 VAG, Ford, GM, Mercedes

Spline M14 VAG, Ford, Rover (plus Ford & VAG gearbox bellhousings)

E12 Female Torx BMW M42-50

Torx T50 Ford, Citreon

Torx T60 Ford 1.8Di

Torx T55 Renault

Torx T70 Ford

9mm Hex key VAG (allen key sawn & welded into a socket)

M12S Special 6 point Nissan

M8S Special 6 point Nissan head and balance shaft bolts



Toyota Idle pulley centre bolt

M10S Special 6 point



Nissan Renault Clutch

M6S Special 6 point



Nissan Balance shaft bolt

8TS Special female 3 point



Smartcar brake socket (plus some GM cars)

Five sided 14mm female socket

Brake socket

Five sided 10mm pentagon (assorted caliper bolts)

Citroen Peugeot Renault brake socket

Five sided 19mm pentogon

Nissan fuel pump

Five sided 12.5mm pentogon



Honda Civic lower control arms

20mm 10 point socket



New type Bosch freewheel alternators.

Torx T50 x long

Spline M10 x long



Modern clamp type diesel injectors.

11mm x 100mm Hex key (allen key sawn & welded into a socket)



Spline type sparkplug

Super long spline socket Citroen C5 fitted with Bosch 385R6 plugs (Laser tools cheapest option, part number: 3949)



Hub nuts.

30mm Six-sided deep socket VAG, Citroen, Fiat, Ford, Lada, Peugeot, Renault, Talbot, GM

30mm Shallow bi-hex VAG

32mm Six-sided deep socket Audi, Citroen, Fiat, Ford, Lancia, Peugeot, Renault, Talbot

33mm Six-sided deep socket VW late Golf front axles

35mm Six-sided deep socket Citroen BX, Rover, Peugeot J7-9

35mm Shallow bi-hex VAG T5

36mm Six-sided deep socket Alfa, Volvo, Citroen, Peugeot, Lancia, VAG (plus Saab ABS brakes & GM clutch bolts)

41mm Six-sided deep socket Alfa, Citroen, Peugeot, Fiat, Ford

45mm Six-sided BMW 5-series, LDV vans

46mm Six-sided BMW 3-series

50mm Bi-hex Transit 80-100-115-120 1988-on

52mm Six-sided Range Rover, Land Rover

56mm Deep bi-hex Transit 130-150-190 1993-on

65mm Bi-hex thin wall Transit 130-150-190 pre-1993

Spline M18 Tamperproof VW late Golf rear hubs



Headlight aligning adjusters.

Ribe M7 x 200mm Alfa, Fiat, Lancia



Early VAG clutch

9mm female spline



Oil filters.

38mm Six-sided GM Vectra 2.0D

27mm Six-sided-shallow Mercedes A-Class (cheap socket ground down to make a shallow one)

24mm Six-sided-shallow BMW V8 engines 2004> (cheap socket ground down to make a shallow one)



Drain plug keys.

Triangular bit Renault

10mm Female Sq BMW, Ford, Renault, Toyota (3/8" socket welded to a bar)

12mm Male Sq Alfa, Fiat, Lancia

10mm Male Sq Peugeot, Citroen , Renault, Volvo (3/8" short socket extension & filed down)

5mm Hex key Mercedes

Spline M16 Tamperproof VAG



VAG late doorhandles.

Spline M4



Fuel filter thru bolts.

13mm x 100mm Hex key Fiat, VAG (allen key sawn & welded into 1/2" six sided impact socket)



Gearbox sump covers.

Ribe M8 x long Alfa, Fiat, Lancia



Idle speed adjuster

Female E4 socket (tiny) Citroen Saxo (Draper sell 1/4" drive long one that fits down the hole)



Motorcycle wheel spindles. (hard black bolts with 19-22-24mm heads, welded into 1/2" sockets). Sealey sell a multipurpose tool for this purpose.

24mm Hex key Suzuki-Honda

22mm Hex key Kawasaki

19mm Hex key Yamaha



Motorcycle single sided swing arm rear spindle nuts

Ducati 999 - 998 - 996 - 916 - Monster - Multistrada - S2R - S4R Preferably six sided socket, but 12point will do the job. 46mm + 41mm needed.

Triumph preferably six sided socket 41mm



Mercedes Sensor Fixings

5 point Torx (male and female)



I truthfully never understand why manufacturers use odd size or style of bolts-fittings. The obvious answer is to try to prevent home mechanics enacting repairs, in truth it may be more to do with automated production tooling.

 

[normspanners]

premmington

You cheated you cant type that quick!!!

 

[500e]

He has got a list to go with the stand for the specials No kidding

 

[Rocketman]

1/4 bsp - 11.8 tapping drill in 10mm water ways.

I can't tell you how many times I have drawn/modelled that size over the years. It's just the standard water ways sizes for injection mould tools.