Denver HT Series Heavy Duty Lathes

This machine is designed for turning and machining large workpieces and steel bar stock. It is well suited to demanding industrial applications, including oil and gas pipeline production, aerospace manufacturing and heavy-duty shaft machining.

1. Spindle and Headstock
-The spindle is available with either a 105 mm (4 in) or 152 mm (6 in) bore and provides 12 spindle speeds. A turbine-type speed-change mechanism helps prevent gear jumping, while the headstock is supported at three points to provide excellent rigidity and stability.

-Models with a spindle bore of 152 mm (6 in) or larger are equipped with an adjustable electromagnetic brake. This allows the braking response to be adapted to different workpiece materials and spindle speeds.

-The gears and shafts are manufactured from high-grade alloy steel and supported by quality NSK bearings, providing durable cutting performance and reduced operating noise.

-A sealed oil-bath lubrication system uses a mechanical pump to provide forced oil circulation, ensuring consistent and effective lubrication throughout the headstock.
The headstock shown is equipped with a 152 mm (6 in) spindle bore and a 12-speed spindle system.

2. Base
The machine bed is manufactured from high-strength Meehanite cast iron and carefully stabilised to maintain alignment and machining accuracy. The bedways are induction-hardened and precision-ground for excellent wear resistance and long service life.
The one-piece cast base provides superior rigidity and stability, supporting greater machining capacity under demanding operating conditions.

3. Gearbox
The quick-change universal gearbox supports metric, imperial, diametrical-pitch (DP), module-pitch (MP) and multiple-start thread cutting without requiring change gears. Its broad threading range and straightforward controls improve operating efficiency and productivity.

4. Tailstock
The tailstock features a two-stage feed mechanism and a saddle-assisted movement system, allowing the tailstock body to travel smoothly along the bed with minimal operator effort.

5. Electrical System
The machine is equipped with a 20 HP motor, a two-stage safety start-up system and overload protection that automatically disconnects the power supply if an unsafe load is detected.

6. Apron
The apron is equipped with rapid traverse, forward and reverse movement, and an integrated safety mechanism. A sealed oil-bath system provides automatic lubrication, while rapid cross-feed improves operating efficiency.

7. Saddle
The saddle surfaces receive an anti-friction treatment and are supplied with regular oil lubrication, reducing wear and ensuring smooth, durable operation.

8. Castings
The principal structural components, including the base, headstock, saddle and tailstock, are manufactured from high-quality FC-30 cast iron. These components are annealed to relieve internal stresses, improve dimensional stability and minimise deformation.

9. Precision Treatment
Critical components—including the bedways, spindle, saddle, cross-slide dovetail surfaces, top slide and tailstock quill—are treated using high-frequency hardening to improve surface hardness, wear resistance and service life.


Capacity
(HT-860) Swing over bed: 860 mm
(HT-960) Swing over bed: 960 mm
(HT-1120) Swing over bed: 1120 mm
(HT-1220) Swing over bed: 1220 mm
(HT-860) Swing over cross slide: 540 mm
(HT-960) Swing over cross slide: 640 mm
(HT-1120) Swing over cross slide: 800 mm
(HT-1220) Swing over cross slide: 900 mm
Distance between centres: 1000/1500/2000/3000/4000/5000/6000/7000 mm

Bed
(HT-860) Swing over gap: 1200 mm
(HT-960) Swing over gap: 1300 mm
(HT-1120) Swing over gap: 1460 mm
(HT-1220) Swing over gap: 1560 mm
Width of Bed: 510 mm (20 in)
Length of gap (spindle end face): 240 mm
(1000) Length of bed: 3300 mm
(1500) Length of bed: 3800 mm
(2000) Length of bed: 4300 mm
(3000) Length of bed: 5300 mm
(4000) Length of bed: 6300 mm
(5000/6000/7000) Length of bed: 7300/8300/9300 mm

Headstock
Spindle bore diameter: 105 mm (4 in); optional 152 mm (6 in)
Number of spindle speeds: HT-860/960/1120: 12 steps; HT-1220: 16 steps
Range of spindle speeds: HT-860: 23-1300 rpm; HT-960/1120: 16-810 rpm; HT-1220: 4-420 rpm
Spindle nose: HT-860: A2-8; HT-960/1120/1220: A2-11

Carriage
Width of Carriage: 660 mm
Cross slide travel: 510 mm
Top slide travel (Compound Slide): 370 mm
Maximum tool shank size: 32 x 32 mm

Tailstock
Diameter of barrel: 125 mm
Travel of barrel: 300 mm
Taper of barrel: MT6

Threads
Lead screw diameter & pitch: 45 mm diameter x 12 mm pitch
Range of metric pitches: 0.8-14 mm (65)
Range of imperial pitches: 2-28 TPI (36)
Range of diametrical pitches: 4-56 DP (36)
Range of module pitches: 0.5-7 MP (22)

Feeds
Feed rod diameter: 32 mm
Range of longitudinal Feeds: 0.050-0.70 mm/rev
Range of cross Feeds: 0.025-0.35 mm/rev

Motor
Main spindle Motor: 15 HP; optional 20 HP (6 in spindle-bore models)
Coolant pump Motor: 1/8 HP
Rapid Motor: 1/4 HP