Hydraulic Quick Coupler Identification Chart

Tools are size-specific — determine your coupler size first.

How to Determine Size

Two easy ways to determine the size and style of your coupler:

  1. Coupler Size Search Tool Fastest

    Search by Part #. Type the part number stamped on your coupler and instantly see its body size (1/4", 1/2", etc.) and style (7241-A, 7241-B, 5675 Ag Poppet, 16028).

    Dashes and spaces don't matter. Can't read it all? Type the first few characters.

  2. How to measure a hydraulic quick connect fitting

    Measure across the male coupler end (not the female end) with calipers, or a tape measure if that's what you have. Calipers in mm are most accurate. For example, a male end that measures 24.5 mm (0.96") is a 1/2" flat face (ISO 16028) coupler.

    Digital calipers measuring across the male coupler end diameter, reading 24.46 mm Best
    Calipers across the male end (tap to enlarge)         Tape measure held straight across the end of the male coupler No calipers?
    Tape measure across the male end (tap to enlarge)

    Got your measurement? Type it here and we’ll match it to a size:

    Millimeters or inches both work. Or compare it to the size chart below.

    See the size chart ↓

No part number? Email Relief@ReliefTool.com 2 photos: a side view of the male coupler end, and a tape measure (or calipers) across the male coupler end diameter (not the female end). We’ll tell you the size — please don’t guess.

Coupler Identification Chart: ISO 16028, 7241-A, 7241-B, 5675

Tap the chart to open it full screen. Pinch or use + / − to zoom. Open full-size image

Not sure which size you have? Don’t guess.

Email us 2 photos of the male coupler end

A side view of the male coupler end, and a tape measure (or calipers) across the male coupler end diameter (not the female end). We’ll tell you the size · relief@relieftool.com

Size chart table — tap your size to shop the set

Measure the male coupler end diameter with calipers (most accurate) or a tape measure, then match it below. These are the same couplers used on Kubota, John Deere, Bobcat, Case and other compact tractors and skid steers.

Male tip diameter by coupler body size and style
Body size ISO 16028 (flat face / skid steer) ISO 5675 / Ag / Pioneer ISO 7241-A ISO 7241-B
1/4"0.64" / 16 mmShop set →0.56" / 14 mmShop set →0.46" / 11.7 mm0.56" / 14 mmShop set →
3/8"0.78" / 20 mmShop set →0.74" / 18.5 mmShop set →0.67" / 17 mmShop set →0.75" / 19 mmShop set →
1/2"0.95" / 24.5 mmShop set →0.80" / 20 mmShop set →0.80" / 20.3 mmShop set →0.93" / 23.6 mmShop set →
5/8"1.06" / 27 mmShop set →———
3/4"1.18" / 30 mmShop set →1.10" / 28 mm1.14" / 29 mmShop set →1.24" / 31.5 mmShop set →
1"1.42" / 36 mmShop set →1.23" / 31 mmShop set →1.34" / 34 mmShop set →1.48" / 37.6 mmShop set →

Found your size on the chart? Shop tools →

Shop by coupler type: Flat face (ISO 16028) · Ag / Pioneer (ISO 5675) · ISO 7241-A · ISO 7241-B

By brand: Kubota hydraulic quick couplers · John Deere skid steer hydraulic couplers · Bobcat hydraulic quick couplers

Coupler Sizes That Measure Close Together

  • 1/2" ISO 5675 / Ag / Pioneer and 1/2" ISO 7241-A take the same tool. At 20 mm and 20.3 mm they are close enough that one 1/2" tool fits both. This is true at 1/2" only — at every other body size, 5675 and 7241-A need different tools.
  • 1/4" ISO 5675 and 1/4" ISO 7241-B are both 14 mm — same diameter, different couplers, and each needs its own tool.
  • 3/8" ISO 5675 (18.5 mm) and 3/8" ISO 7241-B (19 mm) are 0.5 mm apart — also different tools.

For the 1/4" and 3/8" pairs, search the part number stamped on the coupler to be sure. Please don't guess — the wrong size won't fit.

Found your size?

Once Size is determined go to the Tool Sizes Page (Here) to find your tool.

Get your tool →

Not sure yet? Coupler Size Search by Part #

Coupler still won't connect? That's trapped pressure, and the Tractor Relief Tool™ releases it in seconds. See how it works →