The Heat treatment methods for API 5CT casing and tubing is an important factor to differ each grade. Products requiring heat treatment shall be subjected to full body and full length heat treatment. The heat-treated upsetting product should be heat treated full body, full length after upsetting.

A separately heat treated coupling blank is acceptable. If the finishing temperature is higher than the upper critical temperature of the treated steel and the pipe is air cooled, it shall be considered to be normalized.

In case of welding type, weld seam shall be heat treated to a minimum temperature of 540 ℃(1000°F), or a certain treatment method shall be used to make the no untempered martensite structure in the weld.

N80 Type 1 and Type Q

Steel grade N80 type 1 products shall be normalized or normalized and tempered at the option of the manufacturer.

N80Q steel grade products shall be quenched and tempered.

R95

R95 steel grade shall be quenched and tempered.

L80

When tempered at temperatures below 620 ℃(1150°F) , and grade L80 grade 13 Cr may be embrittled.