28pc Assorted Brass Compression Couplings Box - Metric, 4mm to 12mm

28pc Assorted Box of Brass Compression Couplings - 28 brass compression tube couplings covering six metric tube sizes from 4mm up to 12mm, complete with nuts and olives, ready to fit.

A coupling joins two lengths of rigid tube into one continuous run. The olive sits over the tube end, the nut pulls it into the taper inside the body, and the olive bites down to seal on the tube itself - no thread sealant, no flaring tool, no heat. It is the quickest way to join or extend a tube run where it sits, and the box is weighted towards 6mm and 8mm, which is where most fuel, air and coolant work lands.

Box contents (28 pieces total)
2 x 4mm
3 x 5mm
7 x 6mm
7 x 8mm
6 x 10mm
3 x 12mm

Sizes
Six metric tube sizes, 4mm to 12mm

Please note
Compression couplings are not suitable for brake lines. Metric brake pipe is 4.75mm and there is deliberately no 4.75mm fitting in this box - do not substitute the 5mm coupling, as a quarter of a millimetre of clearance on a brake joint is not a fit. A brake repair needs the correct pipe, a flaring tool and proper male and female unions. Tighten the nut firmly but do not overtighten, as an over-crushed olive will leak rather than seal, and a used olive should always be replaced rather than reused.

Suitable for
Fuel and oil lines, pneumatic and air lines, water and coolant pipework, gauge and instrument connections, plant and machinery repair, agricultural and commercial vehicle work, workshop and van stock

Also known as brass compression fittings, metric compression couplers, tube couplings, olive fittings, pipe couplings, or a metric brass compression coupling assortment box.