Operators are advised to establish an equipment maintenance log, recording each curved needle replacement time and usage duration, and to develop differentiated replacement cycles based on the type of sewing materials used (such as denim or leather).
The durability of curved needles varies significantly among different brands. Titanium-coated alloy curved needles can extend service life by approximately 30% compared to standard steel needles. During replacement, attention should be paid to calibrating the clearance between the curved needle and the looper (standard value: 0.05–0.1 mm), and a dedicated needle gauge should be used to check the needle tip angle to ensure proper loop formation and capture with the machine needle. After completion, the machine should be test-run without load to observe whether stitch tension is even and stable.