The 1/4-18 NPT thread repair kit allows for the removal and repair of damaged threads in a tapped hole. They can be replaced by chasing the threads using a thread chaser (a device designed to clean and restore factory threads) or installing an insert that contains new threads of the same size.
Helicoil Thread Repair Kit
1/4-18 NPT Thread Repair Kit - Helicoil Kit - HD Chasen Co
Time-Sert Inch Kit 1/4-32 Provided Insert length is .380 inches. KIT CONTAINS: Drill, Counterbore, Tap, Installation Driver, (5) Steel Inserts.
TIME-SERT 0142 1/4-32 Inch Thread Repair Kit
RAPI-COIL 1/4-20 UNC Thread Repair Helicoil Kit, HSS M2 Tap & Drill, SS 304 Wire Inserts - Made in India: : Industrial & Scientific
Helicoil Master Thread Repair kit 4936 UNF 10-32 1/4-28 5/16-24 3/8-24 1/2-20
Orion Motor Tech Helicoil Thread Repair Kit, 1/4-20 Thread Repair Tool Set with HSS Drill Bit & 30 Thread Inserts, SAE Thread Repair Installation Kit for Rethreading Internal Threads with Carry
RAPI-COIL 1/4-20 UNC Thread Repair Helicoil Kit, HSS M2 Tap & Drill, SS 304 Wire Inserts - Made in India: : Industrial & Scientific
Heli Coil 5540-4 Harley Davidson Thread Repair Kit - 1/4-24 HEL5540-4 HE5540-4
BILITOOLS 1/4-20 inch Thread Repair Kit, HSS Drill Helicoil Repair Kit SAE : Automotive
1/4 - 20 Thread Repair Kit - HD Chasen Co
Fractional Thread Repair Kits - HD Chasen Co