Custom Carbide Reamers for Precision Machining
Ekstrom Carlson’s custom carbide reamers deliver precision and repeatability, whether you need coolant-fed long-reach designs, multi-step taper reamers, or helical reamers for high-volume production. Our expertise ensures you receive tooling tailored to your exact tolerance and coating requirements—even when you’re on a tight turnaround.
High Quality & Accurate Performance
Custom carbide reamers are ideal for finishing high-precision holes in aerospace housings, medical components, or tight-tolerance assemblies. Coolant-fed options enable continuous machining in hard-to-reach or deep cavities, while multi-step designs streamline setups in mold and die work.
Ekstrom Carlson manufactures a wide range of made to order carbide reamers to your requirements. We specialize in long reach reamer designs, coolant fed reamers, and step reamers all designed and built to ensure the highest levels of accuracy for superior tolerance machining. Choose from multi-step, tapered, helical and long reamers.
Additionally, we are able to provide a variety of coatings, special features and cooling systems. This makes us one of the most accommodating custom carbide reamer manufacturers.
Our custom reamers are designed to serve a wide variety of industries where precision hole finishing is critical. From aerospace machining to high-volume automotive production, mold and die making, tool and die shops, and general manufacturing, we deliver reamers that hold tight tolerances and provide long-lasting performance.
Are you looking for other precision options? Please explore our custom step drill bits or flat bottom drills for other solutions.
1. Extended Reach and / or Coolant Fed Reamers
We manufacture extended reach carbide reamers with options for coolant feed holes as a specialty. If you required reamers fast, we can accommodate with our state of the art equipment. Your custom reamer will come at the length you desire with custom geometries optimized for whatever material you may be machining.
2. Custom Step Reamers
Ekstrom Carlson step reamers are made custom to your hole design and tolerance requirements. Let us know what you require and we can provide a quick quotation to meet your reamer tolerances and lengths.
Talk to Our Tooling Experts About Your Application and Get a Precision Reamer That is Up to Your Specs.
Reamer Geometry
The geometry of a reamer’s flutes is critical for maximizing its service life and achieving the desired surface finish of the bore. Choosing the correct flute configuration is essential for optimal performance.
Left-Hand Spiral Flutes for Through Holes
Left-hand spiral reamers are the preferred choice for through holes, which are characterized by an opening that passes completely through the workpiece.
- Chip Evacuation: The left-hand twist acts to push chips forward, ahead of the tool and out the opposite side of the hole. This mechanism prevents previously cut material from accumulating, thereby reducing the risk of scarring the workpiece surface or damaging the reamer.
- Bridging and Stability: This configuration is adept at maintaining contact across interruptions in the bore, such as keyways or cross-holes.
- Performance: They are highly effective when reaming harder materials and typically yield the best dimensional accuracy and surface finish when compared to the other two flute styles (straight or right-hand spiral).
Right-Hand Spiral Flutes for Blind Holes
Right-hand spiral reamers are best suited for blind holes, which are holes that terminate within the workpiece and do not exit the other side.
- Chip Management: The right-hand helix pulls chips backward, drawing them toward the shank end of the reamer. This is vital in blind holes to prevent chips from being compacted at the bottom, which could otherwise lead to tool or workpiece damage.
- Bridging: Like the left-hand spiral, the right-hand design also assists in smoothly traversing interruptions like cross-holes.
- Performance Note: Due to their more aggressive cutting action, right-hand spirals may sometimes produce holes that are slightly oversized. They demonstrate excellent results when working with highly ductile materials.
Straight Flutes for General Use
Straight fluted reamers serve as good all-purpose tools. They are usually more cost-effective than their spiral-fluted counterparts.
- Material Compatibility: They are most effective in non-chip forming materials, such as bronze, free-cutting brass, and cast iron.
- Hole Preference: While they perform adequately in blind holes due to their non-aggressive cutting edge, the optimal condition for straight fluted reamers is a through hole.
- Comparative Performance: If all application specifics are known, a spiral-fluted reamer (either right or left-hand) will generally deliver superior performance and finish compared to a straight-fluted design.
Reamer Functions
| Reamer Type | Flute Geometry | Recommended Hole Type | Chip Management Action | Key Performance Characteristics |
| Left-Hand Spiral | Spiral turns counter-clockwise when viewed from the shank toward the cutting end. | Through Holes | Pushes chips forward and out the exit of the hole. | Excellent finish and size control; ideal for harder materials; highly effective at bridging interruptions (cross-holes/keyways). |
| Right-Hand Spiral | Spiral turns clockwise when viewed from the shank toward the cutting end. | Blind Holes | Pulls chips backward toward the shank, away from the hole bottom. | Performs very well in highly ductile materials; effective at bridging interruptions; may cut slightly oversized due to aggressive geometry. |
| Straight Flute | Parallel to the reamer axis; no twist. | Through Holes (Also works well in Blind Holes) | Non-aggressive; chips fall into flutes for removal. | General purpose and typically the most economical; best for non-chip forming materials like cast iron and brass. |