ISMI Recoil Spring for Smith & Wesson SD9 & SD40 VE

Designed to fit Smith & Wesson Models: SD9 VE, SD40 VE.

Upgrade your Smith & Wesson SD9 & SD40 VE with premium ISMI recoil springs engineered for reliable cycling, improved recoil control, and long-term durability. Available in multiple spring weight options; 15 lb, 18 lb, 20 lb, and a tuner pack containing all spring weights. ISMI allows shooters to fine-tune slide velocity and firearm performance for carry, range, competition, suppressed, or compensated setups. Manufactured from certified aerospace-grade alloys, ISMI recoil springs are heat-treated, shot-peened, and stress-relieved for superior fatigue resistance and consistent spring performance. Compared to standard music-wire springs, ISMI springs maintain tighter tolerances and deliver longer service life with more predictable cycling over high round counts. Whether you're reducing recoil impulse with lighter loads, stabilizing slide timing with factory ammunition, or controlling slide velocity with hotter +P or suppressed setups, ISMI offers a spring configuration to match your build and shooting style. Fine-tune your Smith & Wesson SD platform with proven ISMI recoil spring performance. Available now at NDZ Performance.

Features:

• Multiple spring weight options available: 15 lb., 18 lb., 20 lb., and a tuner pack that contains all spring weights.
• Compatible with Smith & Wesson SD9 & SD40 VE pistols.
• Aerospace-grade chrome silicon or stainless spring materials.
• Heat-treated, shot-peened, and stress-relieved for extended service life.
• Improves recoil management, slide timing, and cycling consistency.
• Precision manufacturing with tighter tolerances than standard music-wire springs.
• Excellent for factory, competition, suppressed, or custom-tuned setups.

These springs utilize the same design and manufacturing technology as used in IndyCar and Formula One racing. In a typical 5 mile race, a valve spring in an IndyCar will go through more than 20,5, compression cycles. Consideration of factors such as modulus, wire diameter, mean diameter, active coils, total deflection, spring relaxation, maximum service temperature, and operating environment, results in you having modern spring technology available for your pistol.

Important: Not compatible with Glock Guide Rods, using these springs with a Glock guide rod in your SD9 or SD40 will result in damage to your firearm. 

See our complete line of Springfield SD9 & SD40 Products here

Note: NDZ always recommends any part be installed by a qualified and trained gunsmith. NDZ promotes the use of safety practices and gear when working on any firearm.