Upper Knife JUKI Replacement Blade for Sergers - 50143403

Keep your serger cutting cleanly with this JUKI upper knife replacement blade, part number 50143403. Designed for compatible JUKI and Bernina (Bernette) overlock and coverstitch machines, this replacement knife helps maintain accurate trimming performance for smooth, professional-looking seams.

This part is a practical choice when your current knife is dull, nicked, or no longer cutting fabric evenly. Replacing a worn upper knife can help restore consistent edge trimming, reduce fraying, and support better stitch quality during everyday sewing and finishing work.

Compatible with a range of machine models including JUKI MO-series and select Bernina (Bernette) models, this blade is intended for users who need a dependable replacement part for routine maintenance. The alternate part number A4142-335-000 is also referenced for cross-checking fit.

Best for:

• Serger and overlock machine maintenance
• Replacing a worn or damaged upper knife
• Improving fabric trimming consistency
• Supporting clean seam finishing on compatible machines

Choose this replacement upper knife to help keep your machine operating at its best and your sewing results looking sharp and professional.