Sunnen HTE-2100

$200,000 - $350,000 Updated 2026-03-16

Key Specifications

bore diameter range

50 - 200 mm (2 - 8 in)

max bore length

3,000 mm (118 in)

stroke length adjustment

Powered (CNC-controlled)

spindle speed range

50 - 500 RPM

stroke rate

Up to 40 strokes/min

surface finish achievable

Ra 0.1 - 1.6 µm

Overview

The Sunnen HTE-2100 is a CNC horizontal honing machine engineered for long-bore honing applications — hydraulic cylinders, gun barrels, pneumatic cylinders, landing gear actuators, and long precision bores in industrial and aerospace applications where the bore length exceeds what vertical honing machines can accommodate. The horizontal configuration enables honing of bores up to 3,000 mm (118 in) in length, covering the full range of long-bore applications from 3-inch hydraulic cylinders through large-diameter landing gear struts and long industrial hydraulic actuators.

The HTE-2100 handles bore diameters from 50 mm to 200 mm (2 to 8 inches) with automatic stone expansion control and in-process gauging. The horizontal arrangement uses Sunnen's horizontal stroke mechanism with powered stroke length adjustment, enabling the honing stroke to be set precisely to the bore length without manual tooling changes. Coolant flow through the honing tool flushes abrasive swarf from the bore throughout the honing process — essential for long bores where gravity does not assist chip removal as it does in vertical honing.

For hydraulic cylinder manufacturers, the HTE-2100 is the primary production honing machine. Hydraulic cylinder bores must achieve Ra 0.4-0.8 µm surface finish with a crosshatch pattern for piston seal performance, bore diameter consistency within ±0.005-0.010 mm along the full bore length, and bore roundness better than 0.005 mm. The HTE-2100's active gauging and CNC control deliver these requirements consistently across production shifts.

At $200,000-$350,000 new, the HTE-2100 is the standard production horizontal honing machine for hydraulic cylinder manufacturers, industrial machine builders, and aerospace actuator manufacturers. Sunnen's application support and global abrasive supply chain provide the ongoing tooling and consumables infrastructure that honing machine operation requires.

Full Specifications

Parameter	Value
Bore Diameter Range	50 - 200 mm (2 - 8 in)
Max Bore Length	3,000 mm (118 in)
Stroke Length Adjustment	Powered (CNC-controlled)
Spindle Speed Range	50 - 500 RPM
Stroke Rate	Up to 40 strokes/min
Surface Finish Achievable	Ra 0.1 - 1.6 µm
Bore Roundness	< 0.005 mm
Bore Cylindricity	< 0.005 mm per 300 mm
In Process Gauging	Sunnen automatic size control
CNC Control	Sunnen CNC with automatic size control
Machine Weight	~4,500 kg (9,921 lb)

Specifications sourced from sunnen.com — verified 2026-03-28

Strengths & Limitations

Strengths

3,000 mm bore length capacity handles the full range from short hydraulic cylinders through long aerospace actuators and gun barrels
Automatic stone expansion and in-process size control delivers consistent bore diameter along the full bore length
CNC-controlled stroke length adjustment enables rapid changeover between different bore length specifications
50-200mm diameter range covers the most common hydraulic and industrial cylinder bore sizes
Horizontal configuration with through-bore coolant flush handles long bore chip management that vertical machines cannot

Limitations

Horizontal configuration requires proper bore alignment and workpiece support for heavy long workpieces
Honing stones are bore-size-specific — changing from 50mm to 200mm bores requires different mandrel and stone sets
For very long bores (2,000-3,000mm), setup time for workpiece loading and alignment is significant
Honing is a finishing operation — significant material removal is not achievable without excessive cycle time

Best For

Hydraulic cylinder manufacturers producing agricultural, industrial, and mobile equipment hydraulic cylinders from 50mm to 200mm bore Aerospace manufacturers honing landing gear strut bores, actuator cylinder bores, and flight control cylinder bores Defense manufacturers honing gun barrel bores and military vehicle hydraulic cylinder bores Industrial machinery builders honing press cylinder bores, crane cylinder bores, and large industrial hydraulic actuator bodies Hydraulic cylinder remanufacturers restoring worn or damaged cylinder bores in large industrial cylinders

Frequently Asked Questions

01 What bore length can the HTE-2100 accommodate?

The HTE-2100 standard configuration accommodates bores up to 3,000 mm in length with the workpiece supported on the machine bed. For bores approaching 3,000 mm, the workpiece must be rigidly supported at multiple points along its length to prevent sagging that would cause taper in the honed bore. Sunnen's application engineers review workpiece weight, diameter, and length when specifying the support and fixturing requirements for long-bore applications.

02 How does horizontal honing maintain consistent bore diameter along the full length?

The HTE-2100 uses a floating stroke mechanism where the honing head strokes the full length of the bore, dwelling at each end of the stroke to prevent undercutting at the bore entrance and exit. The active gauging system measures bore diameter at multiple positions along the bore length during honing. If the bore is tapered (larger at one end), the CNC adjusts the stone pressure profile during the stroke to preferentially remove more material at the tight end, correcting the taper. This active correction ensures cylindricity along the full bore length.

03 What surface finish is required for hydraulic cylinder bores?

Hydraulic cylinder bore surface finish requirements depend on the seal type and hydraulic pressure. Standard hydraulic cylinder seals (lip seals, O-rings with backup rings) typically require Ra 0.4-0.8 µm with a 45-degree crosshatch pattern for good seal seating and oil retention. Higher-pressure applications (above 250 bar) may require Ra 0.2-0.4 µm for leakage control. Servo-hydraulic systems requiring minimal stiction may specify Ra 0.1-0.2 µm. The HTE-2100's CNC program controls the final grit and stone speed to achieve the required surface finish specification.