Type K vs Type L copper pipe

ICS Industries makes this 60 ft coil of ¾ in. nominal Type K copper, annealed to the soft temper. It was new and in stock from COPPERTUBINGSALES, a third-party seller, on Oct 21 and once more on Oct 22, 2026. The listing names ASTM B88, the standard for copper water tube, and NSF 61 for drinking water.

Nominal ¾ in. copper measures ⅞ in. outside. That’s true for K, L and M alike, which is why the same fittings fit all three. The difference is inside. CDA’s Table 14.2a gives Type K at ¾ in. a 0.065 in. wall and a 0.745 in. bore.

Type K is the thickest of the three common types. At ¾ in., its wall is 44% thicker than Type L’s 0.045 in. That extra copper is what you’re paying for, and underground is where it earns its keep.

The coil is the other half of the reason. A 60 ft coil can run from the meter to the house wall with no joint buried in the trench. CDA’s own handbook lists soft coils of 60 and 100 ft for Type K from ¼ to 1 in.

Soft tube also handles a freeze better than hard tube. In CDA’s testing, water in ½ in. soft tube froze six times before the tube burst, and 2 in. tube eleven times. CDA calls that a safety factor for underground services and still says not to let lines freeze.

The rating is 852 psi at 100°F in this soft temper, from CDA’s Table 14.3a. Code asks 160 psi of buried service pipe, under IPC section 605.3. CDA’s tested burst average for ¾ in. Type K soft is 4,200 psi.

Weight runs 0.641 lb per foot, so the full coil is about 38 lb of copper. The same coil in Type L would be about 27 lb. More copper per foot is also why K costs more; the live price is on the button.

I’ve used this coil. Unroll it along the trench rather than pulling loops off the side, or it kinks. One point on markings: CDA says hard tube carries a colored print, green for K, but soft coil only has the incised stamp. Read the stamp on the coil before it goes in the ground.

The GIDS-12L100 is Mueller Industries’ 100 ft coil of ½ in. Type L copper in the soft temper. It was new and in stock from Megamart USA, a third-party seller, on Oct 21 and once more on Oct 22, 2026. The listing gives brand Mueller and the exact model number.

Half-inch Type L measures 0.625 in. outside with a 0.040 in. wall and a 0.545 in. bore, from CDA’s Table 14.2b. Type K at the same size has a 0.049 in. wall and a 0.527 in. bore. On ½ in. tube, the gap between the two is smaller than at ¾ in.

Soft Type L at ½ in. is rated 722 psi at 100°F. That’s about nine times the 80 psi a house is held to under IPC 604.8. CDA’s tested burst average for ½ in. Type L soft is 3,885 psi.

CDA’s own minimum recommendation for buried water services is Type L soft where coils are handier, or Type M hard in straight lengths. Code allows K, L and M underground as long as the pipe is rated 160 psi. So Type L soft is a legitimate service tube in places that allow it.

The catch with this coil is size. IPC section 603.1 says a water service pipe can’t be smaller than ¾ in., so this ½ in. coil isn’t a whole-house service. It’s for the long branch runs where one coil saves you a dozen sweat joints.

Weight is 0.285 lb per foot, about 28 lb for the coil, and it holds about 1.2 gallons of water when full. Soft tube bends by hand, but it also sags between hangers. Support it more often than you would hard tube, and use a bender for tight turns so it doesn’t kink.

Joining is wide open. CDA lists flare and compression fittings for soft tube, along with solder and brazing. Viega’s ProPress guide allows soft tube in sizes from ½ to 1¼ in. Ream every cut end; IPC section 605.13.6 requires cut ends reamed to the full bore.

I’ve used this coil. My call: when a run is long and a joint inside a wall would worry you, a single soft coil is the cleaner job. Mark the stamp side up as you pull, so the next person can read Type L on it.

VENTRAL, a US pipe fabricator, cuts this hard-temper ½ in. Type L tube to 60 in. lengths. The listing puts the outside size at 0.625 in., the true OD of ½ in. nominal copper. VELOCITY/VENTRAL, a third-party seller, had it new and in stock on Oct 21 and again on Oct 22, 2026.

Type L is the everyday supply tube inside a house. It has the same 0.625 in. outside size as Type K at ½ in., so every ½ in. sweat, press and push fitting fits both. The difference is a 0.040 in. wall against K’s 0.049 in.

That thinner wall gives a slightly bigger bore. CDA’s tables put ½ in. Type L at 0.233 sq in. of bore area against 0.218 for Type K. At 3 GPM, CDA’s friction table works out to 6.2 psi lost per 100 ft in Type L and 7.4 in Type K.

In the hard temper, ½ in. Type L is rated 1,242 psi at 100°F. Solder it with 95-5 and the joint, rated 1,090 psi, sets the limit instead of the tube. Braze it and the rating drops to the soft figure, 722 psi, because the heat softens the copper.

Five feet is a handy length. The standard straight length in CDA’s Table 14.1 is 20 ft, which doesn’t fit in most cars. For a repair under one sink or a short reroute, one or two 5 ft pieces usually cover it.

Hard tube carries a colored print along its length, blue for Type L. That print, plus the incised stamp with the type, maker and country, is how you’ll know what’s in your walls years from now.

Cut it square with a tubing cutter and ream the burr out. IPC section 605.13.6 requires cut ends reamed to the full bore for soldered joints, and press-fit makers ask for the same. A burr left inside costs flow and can start erosion at the fitting.

I’ve used this tube on branch lines. My call: for indoor water lines, Type L is the right weight. Type K indoors is extra copper for no gain you’d see at the tap, and Type M’s thinner wall leaves less copper to lose to a pinhole.

This is a 5 ft straight length of ¾ in. nominal Type K copper in the hard, drawn temper, made by ICS Industries. It was new and in stock from COPPERTUBINGSALES on Oct 21 and once more on Oct 22, 2026. The listing names ASTM B88 and C12200 copper, which CDA says is the copper customarily used for water tube.

It has the same 0.875 in. outside and 0.065 in. wall as the soft coil above. The difference is temper. Hard tube is stiff and straight, and CDA rates ¾ in. Type K hard at 1,466 psi at 100°F, against 852 psi soft.

Five feet is a repair length. The usual job is a leak at the meter or curb stop, a section a shovel or a root found, or a riser coming up through a slab. You cut out the bad section and splice this in with two couplings.

Matching the type matters on a repair. A Type L patch in a Type K line works under pressure, but it’s the thinner spot in the run. If the old line lasted decades in that soil, use the same wall it was built with.

Watch the joint method. If you braze, CDA says to use the annealed rating, because the heat softens the tube near the joint. That’s still 852 psi for ¾ in. Type K, more than five times code’s 160 psi minimum for service pipe.

Service repairs are often in a wet hole. Solder won’t take on a line that’s still dripping. Viega’s ProPress fittings press onto B88 Types K, L and M, and our guide to pressing a wet line covers what press makers allow when the water won’t fully stop.

Hard tube carries a green print for Type K, plus the incised stamp. Cut it with a tubing cutter, not a hacksaw, and ream the inside edge before it goes into a fitting.

I’ve used this tube for patches. My call: keep a short length of K hard on the truck for service repairs. For anything longer than one splice, a soft coil and fewer buried joints is the better job.