Question 1

What hydraulic fittings are on UK tractors?

Accepted Answer

Most UK and European tractors (New Holland, Claas, Fendt, Massey Ferguson, JCB) use BSP (British Standard Pipe Parallel) fittings as standard. Older or North American equipment (John Deere, Case IH) may use JIC 37° flare fittings. Modern high-pressure systems increasingly use ORFS (O-Ring Face Seal) to prevent leaks.

Question 2

How do I tell a BSP fitting from a JIC fitting?

Accepted Answer

The easiest way is to look at the mating face. BSP fittings have a flat face that seals with a bonded seal (dowty washer) or a tapered thread (BSPT). JIC fittings have a 37° cone/flare seat — you will see an angled taper on the male end that sits into a matching cone in the female. If you have callipers, measure the thread O/D: a 1/2" BSP thread measures 20.96 mm O/D, whereas a -8 JIC (3/4-16 UNF) measures 19.05 mm O/D.

Question 3

What is the difference between BSP and BSPT?

Accepted Answer

BSPP (G-thread) is a parallel thread that relies on a face seal or bonded washer for sealing. BSPT (R-thread) is a tapered thread that seals on the thread taper itself, similar to NPT. Most hydraulic port fittings use BSPP (parallel). BSPT is more common in plumbing and low-pressure applications.

Question 4

What does the dash size mean on a hydraulic hose?

Accepted Answer

The dash size is a shorthand for the hose inner diameter in 1/16 inch increments. So -8 hose has an inner diameter of 8/16" = 1/2" = 12.7 mm. -6 hose = 6/16" = 3/8" = 9.5 mm internal bore. The same dash number is used for the matching fitting size — a -8 hose takes -8 JIC or -8 ORFS fittings.

Question 5

What is ORFS and why is it used?

Accepted Answer

ORFS stands for O-Ring Face Seal (SAE J1453). It uses a flat face with a recessed O-ring groove that compresses against the mating face to create a zero-leak seal. ORFS is increasingly specified on modern tractors and high-pressure systems because it is more reliable than cone or tapered thread seals under vibration and thermal cycling. It is commonly found on Fendt, Claas and newer Massey Ferguson equipment.

Question 6

How do I measure a hydraulic fitting to identify the size?

Accepted Answer

Use digital callipers to measure the thread outer diameter. Then count the threads per inch (TPI) using a thread pitch gauge or by counting threads in one inch. Cross-reference both measurements against the BSP, JIC or ORFS tables. For example: if the thread O/D measures 20.96 mm and you count 14 TPI — that is a 1/2" BSPP fitting.

Size	Thread	O/D (mm)	TPI	Spanner (AF)
1/8"	1/8 BSPP	9.73	28	14 mm
1/4"common	1/4 BSPP	13.16	19	19 mm
3/8"common	3/8 BSPP	16.66	19	22 mm
1/2"common	1/2 BSPP	20.96	14	27 mm
3/4"common	3/4 BSPP	26.44	14	32 mm
1"	1 BSPP	33.25	11	41 mm
1¼"	1¼ BSPP	41.91	11	50 mm
1½"	1½ BSPP	47.80	11	55 mm
2"	2 BSPP	59.61	11	70 mm

Hydraulic Hose & Fitting Size Guide

Useful Equipment

Frequently Asked Questions