DHG Tech Inc. · Orbit Series
Bar centering units for multi‑spindle lathes
Twenty per cent more spindle speed, on the bar you already buy.
Commercial bar is never perfectly straight, and at working speed it whips. Orbit holds that movement inside a controlled clearance at the spindle entry — one unit per spindle, on six‑spindle and eight‑spindle machines alike. Less vibration and less noise, a better finish, longer tool life, and a machine that wears less.
+20% spindle speed
A working figure
Material and bar diameter set the exact gain
Under 10 minutes
Jaw pair change‑over, per spindle
Diameter and profile both change with the pair
308 jaw types
71 native in inches
Round, hex and square in every size
Twenty per cent is spindle speed, not cycle time: indexing and tool change are your machine’s, not ours. Tell us the material and the bar diameter and we will say what to expect on your job.
01 · What it does
A quiet bar runs faster
Bar stock does not arrive at the spindle politely. It whips, it drums, and it carries every bit of that into the cut.
A centering unit is the last thing the bar passes through before it enters the spindle. Contain it properly there and the whip stops being the machine’s problem: the cut steadies, the finish steadies, and the tool stops absorbing shocks nobody sized it for. The shop gets quieter, which the people in it notice long before the spreadsheet does.
None of that is free speed. It is speed you were already paying for and could not use.
The harder the material, the more it is worth.
Stainless, high-nickel alloys, titanium, hard bronze: heavier cuts, a stiffer chip, a bar with far less patience. A loose channel turns every pass into an argument with the machine, and that argument gets settled the only way it can be — by backing off the feed. Orbit earns most on exactly the jobs a shop charges most for.
02 · Applications
Your machine is probably already on the list
Orbit is not a design waiting for its first installation. The application catalogue behind it was built one machine at a time, over years of them — and it is the reason a quotation comes back as an answer instead of a question.
Centering units in this family have been built, fitted and run on automatic lathes from:
Schütte
SF · SG · S PC · SCX
INDEX
MS series
Mori-Say
TMZ & classic ranges
Gildemeister
GM · GMC · GS
Tornos
SAS
Wickman
Inch-series multis
Six-spindle and eight-spindle. Lathes prepared for the bar feeder and lathes that never were. Prepared spindles, unprepared spindles, nose-piece versions — the interface is built to suit, and it is part of what you are buying rather than something you are left to sort out on the floor.
And if your combination is not one we have already built, it is a drawing. Not a research project.
03 · Two types
Jaw type and star type
Same body, same rotating base, same mounting. What changes is how the bar is held.
Jaw type
Multi-spindle automatic lathes
Two opposed jaws close to a channel cut for the bar you run. As the pusher comes through it meets the slider, compresses the spring, and the jaws ride their track and open to let the bar pass. The spring closes them behind it. Every bar, every cycle.
Round, hexagon and square, in inch and metric sizes.
Star type
Single-spindle automatic lathes
Three cylinders at 120°, riding cam profiles and opening outward as the pusher advances. Three-point centering, nothing size-matched to change, and the same automatic cycle.
Takes the upper part of each unit’s capacity, where the jaw range ends. Supplied in sets of three.
Neither type has an operator adjustment, and that is deliberate. The part you fit is the specification — which means it cannot be set wrong at four o’clock on a Friday.
04 · Inch sizes
Inch sizes with jaws of their own
American shops buy bar in inches. Centering jaws grew up on a metric ladder. The usual answer to the mismatch is to hand you the nearest metric size and call it close enough.
For a part whose entire function is a controlled clearance, close enough is not a specification. Across much of the inch ladder the nearest metric jaw sits several times looser than the design intends for that size. It will run. It will simply run loose — and the containment you are paying for has quietly gone.
So the inch sizes have jaws of their own: specified, tabulated and available right across the range, closing on the clearance the design intends rather than on whatever the metric list happened to have nearest.
Inch and metric are quoted the same way, and the size comes back to you stated in the units you work in.
Bar range by unit size
| Unit size | Round | Hexagon A/F | Square |
|---|---|---|---|
| GM-24 | 1/8 – 11/16 in | 1/4 – 11/16 in | 5/16 – 3/8 in |
| GM-30 | 3/16 – 13/16 in | 1/4 – 3/4 in | 3/8 – 13/16 in |
| GM-40 | 3/16 – 1-1/8 in | 1/4 – 1-1/8 in | 1/4 – 13/16 in |
| GM-52 | 1/4 – 1-5/8 in | 3/8 – 1-9/16 in | 1/2 – 1-1/2 in |
The unit size is set by the machine, not by the bar. The bar decides which jaw goes into it.
Complete centering units are available on the GM-52 today. Jaws and jaw kits are available across all four sizes, the inch series included.
05 · Selection
You should not have to read a table to find your jaw
Two centering types, three bar profiles, a size ladder that runs from the smallest automatic lathes to the largest. Tell us what you are running and we come back with the answer — not with a catalogue.
The unit size is set by the machine: it is the interface to the lathe and to the bar feeder, not a bar capacity, and the ranges overlap almost completely. The bar then chooses the type and the variant inside it. That is easy to get wrong from a page and hard to get wrong from a conversation.
What to send us
- Lathe make and model
- Bar feeder or bar loader, if you know it
- Bar profile — round, hexagon or square
- The bar sizes you actually run, in inches or millimetres
- Whether you are replacing units already in service
Back comes the unit size, the type, the jaw or cylinder codes, a price and a delivery. And if your lathe and loader are a pair we have already built, it comes back fast — because that work was done years ago.
06 · Delivery
The jaws are the running cost, so the jaws are what we keep moving
No shop ever stopped because a centering body wore out. Shops stop because the jaw for the size they just won an order for is still weeks out.
Jaws in any size in the range, the inch series included, and maximum sectors: three to five working days — and the uncommon size ships to the same lead time as the common one. Cylinder sets, bodies, bases and the remaining wear parts are quoted with the enquiry.
These lead times apply to the DHG stock programme in the United States, effective 1 November 2026. Orders taken before that date are quoted individually and scheduled into the first production run.
Jaws and cylinders wear. The body, the guides and the tube last the life of the machine. Jaws go out in matched pairs, cylinders in threes, and both drop into the units already on your floor.
07 · Supply
What we supply
- Complete centering units — jaw or star type, assembled.
- Jaw pairs and jaw kits — round, hexagon and square, inch and metric.
- Cylinder sets for the star type, supplied in threes.
- Wear and service parts — springs, pushers, locking pins, guides, star cams, inner and outer rings, tubes, maximum sectors.
- Dedicated types for bar sizes outside the published ladder.
- Machine applications — the interface to your lathe and to your bar feeder, from the catalogue or drawn for you.
- Documentation — dimensional drawings, operation and maintenance manual, selection tables in inches and millimetres.
A DHG design, drawn, specified and manufactured in the United States.
Documentation
The Orbit leaflet, in four pages
What a centering unit is for, what one unit covers, what changes when the bar changes, and what is supplied with it. One document for the shop floor and for the person who signs the order.
PDF · A4 · 4 pages · 0.5 MB
Tell us what you are running
Machine, bar feeder, bar programme. That is enough to start.
Product definition
The drawings, dimensional tables, material specifications and documentation of the Orbit Series are DHG Tech documents. Orbit Series units are manufactured and assembled in the United States. Lathe and bar-feeder makes and models are named for compatibility reference only; all trade marks belong to their respective owners.