Big-Sert Technical Information
Complete engineering data, specifications, and kit information for Big-Sert oversize thread repair systems
Engineering Data & Specifications
INCH & METRIC Engineering Data
Complete specifications for drill sizes, counterbore dimensions, and tap sizes
Universal Head Bolt Kits & Tap Guides
Universal Big-Sert Head Bolt Kits
Used when a Helicoil or coil style insert has failed - includes tap guide specifications
Spark Plug Thread Repair Kits
Big-Sert Spark Plug M14×1.25
Complete kit specifications for M14×1.25 spark plug thread repair - repairs oversized holes as large as .660 inches or 16.8mm
Installation Process
Step 1: Assess the Damage
Measure the existing hole to determine if Big-Sert is required. If the hole is already larger than standard Time-Sert drill size, Big-Sert may be your only option.
Step 2: Select Proper Kit
Choose the Big-Sert kit that matches your required internal thread size. The kit includes the oversize drill, counterbore, tap, and installation tool.
Step 3: Drill to Size
Drill the hole to the Big-Sert specification. This will be larger than a standard Time-Sert drill size. Ensure the drill is perpendicular to the surface and drill to the full depth.
Step 4: Counterbore
Create the recessed lip using the Big-Sert counterbore tool. The counterbore depth is critical for proper insert seating.
Step 5: Tap Threads
Tap the hole using the Big-Sert tap. Use cutting fluid and ensure clean, complete threads to full depth.
Step 6: Install Insert
Install the Big-Sert insert using the driver tool. The roll-forming action locks the insert permanently in place.
Big-Sert vs Standard Time-Sert
| Feature | Standard Time-Sert | Big-Sert |
|---|---|---|
| Outer Diameter | Standard oversize | Larger oversize |
| Use Case | Normal thread damage | Oversized holes, severe damage |
| Thread Strength | Stronger than original | Maximum strength |
| Material Removal | Minimal | More parent material removed |
| Installation | Same process | Same process, larger tools |
| Locking mechanism | Excess material at base of insert | Cam-locking roll pin |
Important Application Notes
- •Oversize Repair: Big-Sert is designed for holes that are too damaged for standard Time-Sert repair
- •Second-Stage Repair: Ideal when previous Helicoil or coil-style insert repairs have failed
- •Material Compatibility: Works in aluminum, cast iron, and other parent materials
- •Insert Materials: Available in carbon steel and aluminum depending on application requirements
- •Tap Guides: Always use tap guides to ensure threads are square to the surface of the hole
Need Help Selecting the Right Kit?
Our technical team can help you determine the correct Big-Sert kit for your specific application and answer any questions about installation procedures.