QA1 10CS400 Chrome Coil Spring 2-1/2" ID 10" Free Length 400 lbs/in

The QA1 10CS400 is a chrome-plated coil spring featuring a 2-1/2" inside diameter, 10" free length, and a 400 lb/in spring rate. Designed for coilover shock applications in performance street, drag racing, and circle track builds, this spring delivers the consistent, linear rate behavior that serious builders demand.

Constructed from high-tensile chrome silicon (CrSi) alloy wire, the 10CS400 is cold wound, heat treated, and shot peened to maximize fatigue life, dimensional accuracy, and long-term durability. Both ends are ground square to ensure straight, consistent seating and accurate operation in any coilover application.

Key Features:

• Spring Rate: 400 lbs/in linear rate
• Inside Diameter: 2-1/2" — compatible with standard 2.5" I.D. coilover hardware
• Free Length: 10"
• Material: High-tensile chrome silicon (CrSi) alloy spring wire
• Finish: Polished and chrome plated for show-quality appearance
• Manufacturing Process: Cold wound, heat treated, and shot peened
• Ends: Ground square at both ends for straight, accurate operation
• Identification: Free length and spring rate clearly marked on the spring
• Warranty: Lifetime guaranteed to remain within 2% of original free height and rate under normal operating conditions
• Made in the USA

The polished chrome plating provides a bright, show-quality finish that looks as good as it performs — ideal for hot rods, street rods, and classic muscle builds where appearance matters. The 10CS400 is part of QA1's broad lineup of 2.5" I.D. coil springs, available in free lengths from 6" to 14" and a wide range of spring rates to suit any build.