In mechanical machining, drilling or boring alone is often insufficient when strict requirements for dimensional accuracy, roundness, and surface roughness (e.g., IT6–IT8 grade, Ra 0.8–1.6 μm) are demanded.
This is where the Reamer becomes essential. As a critical finishing tool, it does not aim to remove large amounts of material. Instead, it refines the pre-drilled hole through micro-cutting, delivering a high-precision, high-finish result.
As a dedicated manufacturer of cutting tools, we provide a comprehensive range of reaming solutions designed to meet these exacting standards.
What is a Reamer?
A reamer is a rotary cutting tool with multiple cutting edges (typically 4 to 12 flutes), designed to enlarge and finish a previously drilled or bored hole. With a minimal cutting allowance (usually 0.05–0.3 mm per side), reamers operate smoothly with low vibration, effectively improving the geometric accuracy and surface quality of the hole.
Key Functions of a Reamer
Why add a reaming step to your process?
1. Dimensional Accuracy: Controls hole diameter tolerances within ±0.01 mm.
2. Geometric Correction: Corrects errors from drilling, such as eccentricity, bell-mouthing, or ovality.
3. Surface Finish: Easily achieves Ra 1.6, with high-quality reaming capable of reaching Ra 0.4.
4. Consistency: Ensures position consistency and interchangeability, crucial for mass production.
Types of Reamers and How to Select
Choosing the right reamer is critical. Below is a breakdown of common types and how our products fit your needs.
1. By Usage Method
● Hand Reamers: Feature a square drive on the shank for manual operation. They have a longer tapered lead (approx. 1°–1.5°) for easy alignment. Ideal for maintenance or low-volume assembly.
● Machine Reamers (Our Specialty): Installed on drill presses, lathes, or CNC machining centers for automatic feed. They feature a shorter chamfer, high rigidity, and high efficiency. We specialize in manufacturing high-precision machine reamers tailored for automated production lines.
2. By Construction
● Solid Reamers: The body and cutting edges are integral. Usually made of HSS or Solid Carbide. Best for small to medium diameters (Φ3–Φ20 mm).
● Adjustable Reamers: Allow for micro-adjustments of diameter to compensate for wear or handle specific tolerance bands.
● Brazed/Indexable Reamers: For large diameters (>Φ50 mm), we offer solutions with brazed carbide tips or mechanically clamped inserts to reduce costs and facilitate tool changes.
3. By Flute Direction
● Straight Flute: Simple structure with easy chip evacuation. Suitable for through-holes and short-chipping materials (e.g., Cast Iron, Brass).
● Spiral Flute:
◇ Left-Hand Spiral: Pushes chips forward (down). Ideal for through-holes to create a mirror finish.
◇ Right-Hand Spiral: Pulls chips backward (up). Essential for blind holes to prevent chips from clogging the bottom. Excellent for sticky materials like Stainless Steel and Superalloys.
4. By Material
● High-Speed Steel (HSS): Versatile and cost-effective. Suitable for general carbon steel and aluminum.
● Solid Carbide Reamers: The core of our product line. Designed for high-hardness materials (Hardened Steel, Nickel Alloys) and high-efficiency CNC environments. They offer superior rigidity and wear resistance compared to HSS.
● Coated Reamers (TiN/TiAlN): Our advanced coatings can extend tool life by 30%–100% by reducing friction and heat.
5 Key Tips for the Reaming Process
To maximize the performance of our reamers, follow these guidelines:
1. Pre-Hole Quality: The starting hole must be straight and free of hardened layers. Position accuracy is key.
2. Stock Allowance: Critical balance is needed. Too little causes rubbing/burnishing; too much overloads the tool. Generally, leave 0.1-0.2mm on diameter.
3. Gentle Parameters: Reaming speeds are typically lower than drilling (Steel: 10–20 m/min; Aluminum: 30–60 m/min) with moderate feed rates.
4. Coolant Strategy: Essential for flushing chips and lubrication. For Stainless Steel or Titanium, use oil with Extreme Pressure (EP) additives.
5. Never Reverse: When retracting a machine reamer, maintain forward rotation. Reversing will drag chips against the finished wall, ruining the surface.
Typical Applications
Our reamers are trusted in industries requiring zero-defect holes:
◇ Precision spool bores in Hydraulic Valves.
◇ Main bearing caps in Engine Blocks.
◇ High-tolerance dowel pin holes in Aerospace Structures.
◇ Guide bushing holes in Mold & Die making.
Conclusion
Although reaming is often the final step in hole making, it determines the assembly performance and longevity of the part. Understanding the types—from HSS straight flutes to our advanced Solid Carbide Spiral Reamers—is the first step toward perfection.
Looking for the perfect reamer for your project? Contact us today to explore our high-precision inventory and custom solutions.
