38C2 (AFNOR designation, Wnr. 1.7003, DIN 38Cr2) is a low-alloy chromium structural steel with roughly 0.35-0.42% carbon and a modest 0.4-0.6% chromium addition. The chromium doesn't transform this into a deep-hardening tool steel the way it would at higher percentages — instead, it gives 38C2 medium hardenability and a useful boost in strength and wear resistance over a plain carbon steel of similar carbon content, without pushing the alloy content high enough to complicate machining or heat treatment. It's the same design logic behind AISI 5140, its closest American cross-reference, and the two grades are commonly substituted for one another in general engineering work.

38C2 is typically supplied normalized or as quenched-and-tempered bar stock, and it responds well to through-hardening in small-to-medium sections. Typical applications include bolts, shafts, gears, and machine parts that call for more strength and toughness than a plain carbon steel can offer but don't need the deeper hardenability of a 41xx or 43xx grade. It also forges and welds with reasonable ease compared with more heavily alloyed steels, which keeps it a practical choice for fabricated components that are finish-machined after forming.

38C2 machines in the same general territory as other lean Cr-alloyed medium-carbon steels: noticeably tougher and more abrasive than a plain carbon steel of the same carbon content, but well short of the cutting forces and heat generation you'd see on a heavily alloyed grade. In the normalized condition it cuts cleanly with standard coated carbide, while quenched-and-tempered stock pushes cutting forces and flank wear up in proportion to the hardness ordered.

Chip formation is generally favorable, producing continuous-to-segmented chips that break well with a properly matched chipbreaker, similar in behavior to 5140 and other lean chromium alloy steels. As hardness increases toward the top of the quenched-and-tempered range, chips shorten and edge temperatures climb, which is where a coated grade with good hot hardness starts to earn its keep over an uncoated edge.

Rigid setups and consistent feed engagement matter more on this steel than on plain carbon grades, since light or interrupted cuts encourage work hardening at the chromium-alloyed surface. A positive-rake geometry that keeps the tool cutting rather than rubbing, paired with a wear-resistant coated grade, gives the most consistent results across the normalized-to-Q&T hardness range this material is typically supplied in.