Copper Tube Flaring Kit Explained: A UK Buyer's Guide

Why refrigeration copper needs a proper kit

Refrigeration and air conditioning line sets use soft (annealed) copper with thin walls. That softness is what lets you bend and flare it — but it is also why a crude clamp-and-cone can bite, thin or split the tube instead of forming a smooth cone. If you have been fighting cracked flares, the tube is usually not the problem; the tool is.

A proper HVAC kit versus a generic automotive set

If you have been using a general automotive or plumbing flaring set and it keeps splitting softer refrigeration copper, here is what actually separates a purpose-built copper tube flaring kit from a cheap all-rounder:

• Eccentric cone, not a plain screw cone: an eccentric cone rolls the copper progressively, spreading the work so the wall is far less likely to split.
• Depth control: a clutch that slips at the right point stops the over-flaring that thins and cracks soft tube.
• Correct size seats: a flaring bar with properly sized 1/4"–3/4" seats holds the tube square; automotive kits often skip the sizes HVAC needs.
• Cutter and deburrer included: because a ragged or burred cut cracks even with a good cone.

Being wary after a bad purchase is fair. The tell-tale of a proper kit is that it names refrigeration copper and aluminium, lists the imperial sizes, and includes the prep tools — not just a bag of cones.

The sizes you actually need

For UK refrigeration and aircon work, look for a full 1/4" to 3/4" imperial spread (1/4, 5/16, 3/8, 1/2, 5/8, 3/4). That range covers the common line sets; a kit missing the middle sizes will leave you improvising on site.

What to check before you buy — and the honest limits

Before parting with money, check the cone finish, that the bar carries your sizes, and that a cutter and deburrer are in the box. A good kit dramatically reduces cracked flares — but it is not a licence to skip prep. Work-hardened tube that has been bent and re-bent, or tube projected too far above the clamp, can still split. Anneal or cut back suspect tube, and let the tool do the rolling.

Putting the kit to work on a split install? See the on-site contents and workflow in the air conditioning pipe flaring kit guide, and the basics of the flare angle in the 45 degree flare tool guide.

FlariTool's Pro Copper Pipe Flaring Tool Kit (£178.22) is a purpose-built copper tube flaring kit: a 45° eccentric cone, a clutch, 1/4"–3/4" seats, plus a 4–28mm cutter and deburrer in a hard case, backed by a 12-month trade warranty.

Frequently Asked Questions

Can I use an automotive flaring kit on refrigeration copper?

You can, but it is risky. Automotive sets are built for stiffer brake line and often lack HVAC sizes, so they tend to split soft refrigeration copper. A purpose-built copper tube flaring kit is a safer choice.

Why does copper crack when I flare it?

Usually because of a burred or oval cut, over-flaring, or a plain cone biting thin soft tube. An eccentric cone with depth control reduces all three.

What sizes should a copper tube flaring kit cover?

A full 1/4 inch to 3/4 inch imperial range covers the common UK line sets used in refrigeration and air conditioning.

Do I need to deburr copper before flaring?

Yes. A burr left inside the cut can tear the flare and shed debris into the system, so ream and clean the end before forming the cone.