3-Piece Inch Size TiN-Coated HSS Step Drill Bit Set | Precision
Performance for Metal, Electrical & Plumbing Work
Enhance your workshop efficiency with the XINGRUI 3-Piece Inch Size
Step Drill Bit Set, crafted for professionals who demand precision,
durability, and smooth performance. Each bit is made from
industrial-grade High-Speed Steel (HSS) and coated with Titanium
Nitride (TiN) — ensuring superior hardness, low friction, and
exceptional heat resistance for extended tool life.
Designed for metal, aluminum, copper, brass, stainless steel (thin
gauge), and plastic, this set is ideal for electricians, metal
fabricators, HVAC technicians, plumbers, and automotive engineers.
Product Manufacturing Process
Material Selection: Premium HSS (M2 grade equivalent) is selected
for its toughness and wear resistance.
Heat Treatment: Each blank undergoes precise hardening and
tempering to achieve optimal core hardness and durability.
CNC Precision Grinding: Steps and flutes are CNC-ground to tight
tolerances for perfect concentricity and sharp cutting edges.
TiN Coating Application: A PVD Titanium Nitride coating is applied
under vacuum conditions, forming an ultra-hard gold surface (HV ≈
2300).
Quality Inspection: Each bit passes through runout, hardness, and
cutting tests to guarantee performance consistency and smooth chip
evacuation.
Key Features
Premium HSS Construction: Engineered for strength, durability, and
resistance to wear under high-speed drilling.
TiN Gold Coating: Reduces friction, dissipates heat, and improves
cutting efficiency — extending tool life up to 6x compared with
uncoated bits.
Precision-Ground Steps: Clean, accurate holes with built-in
deburring edges for a professional finish.
135° Split-Point Tip: Prevents walking and ensures faster, more
accurate drilling starts.
Universal Fit: Round shank fits all standard drill chucks and drill
presses.
Protective Storage Case: Metal box with labeled compartments for
easy identification and portability.
Technical Specifications
| Feature | Specification |
|---|
| Material | High-Speed Steel (HSS) |
| Coating | Titanium Nitride (TiN) – Gold |
| Process | Hardened, Tempered & CNC-Ground |
| Tip Angle | 135° Self-Centering |
| Shank | Round |
| Sizes | Bit 1: 1/8"–1/2" (13 steps) Bit 2: 3/16"–7/8" (9 steps) Bit 3:
1/4"–1-3/8" (10 steps) |
| Application | Metal, Stainless Steel (Thin), Aluminum, PVC, Brass, Plastic |
Applications
Electrical: Ideal for cutting holes in switch boxes, control
panels, and junction boxes.
Metal Fabrication: Perfect for enlarging holes and drilling thin
metal plates up to 4mm.
Plumbing & HVAC: Efficiently drills holes in pipes, ducts, and
sheet metals for installations.
Automotive: Suitable for vehicle body panels, brackets, and repair
work.
DIY & Maintenance: Multi-size solution for workshop and home
improvement tasks.
How to Use for Best Results
Operate between 300–800 RPM depending on material hardness.
Apply cutting oil for steel or stainless steel to extend lifespan
and improve finish.
Use steady, controlled pressure — let the bit do the work.
FAQ
Q: Can I use these bits for stainless steel?
A: Yes, they are suitable for thin-gauge stainless steel (≤4mm).
Always use cutting oil and moderate speed.
Q: How long do they last?
A: The TiN coating provides up to 6× longer life than standard
uncoated HSS bits under similar conditions.
Q: Are these bits made to American standard sizes?
A: Yes, this set includes inch-size increments, making it ideal for
U.S. and international users working with imperial measurements.
