Heli-coil 4944-10 Hand Sti Tap M10 X 1.25 Metric Fine

Product Description

The HELI-COIL 4944-10 is a hand STI tap designed for cutting threads in pre-drilled holes to accept HELI-COIL wire thread inserts. Sized at M10 x 1.25 metric fine with a D3 thread limit and 5H class of fit, this tap produces precise, oversized threads that allow a standard insert to restore the fastening hole to its original M10 x 1.25 specification. Constructed from high-speed steel with a bright finish, it features 4 flutes and a plug chamfer for controlled hand tapping. Thread length is 42.07 millimeters with an overall length of 85.72 millimeters. Machinists, mechanics, and maintenance technicians use this tool in thread repair and manufacturing applications.

This tap is suited for thread insert preparation in both production and repair environments. The plug chamfer makes it appropriate for through-holes and deeper blind holes where a starting taper is not required. It is rated for use in aluminum, magnesium, mild steel, and stainless steel, making it versatile across automotive, aerospace, and general industrial maintenance applications. The 4-flute design supports clean chip evacuation during hand tapping operations.

Key Features

• M10 x 1.25 metric fine thread form, D3 thread limit, 5H class of fit for accurate insert-ready threads
• High-speed steel construction for durability across a range of workpiece materials
• 4-flute geometry promotes chip clearance during hand tapping
• Plug chamfer style suits through-holes and moderately deep blind holes
• Bright finish provides corrosion resistance during storage and use
• Compatible with aluminum, magnesium, mild steel, and stainless steel workpieces

Compatibility

Designed for use in HELI-COIL STI thread insert systems requiring an M10 x 1.25 metric fine tapped hole. Intended for hand tapping applications where thread repair or insert installation is performed on compatible workpiece materials.

Installation Notes

This tap is intended for hand tapping use by qualified machinists or mechanics familiar with thread insert repair procedures. Secure the workpiece before tapping and use appropriate cutting fluid for the workpiece material, particularly when tapping stainless steel or aluminum. Apply steady, controlled torque with a tap wrench and back off periodically to break chips. Always follow HELI-COIL system installation procedures and manufacturer guidelines for insert sizing and drill preparation.