Views: 0 Author: Nancy Liu Publish Time: 2026-06-22 Origin: Zhenghao Machinery
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In CNC production, the spindle is the only part of the machine that generates revenue. Every minute the spindle is cutting metal, the machine is earning its keep. Every minute the spindle is idle — while an operator loads parts, changes jaws, re-aligns a vise, or waits for the previous cycle to finish — is lost production capacity that cannot be recovered.
For most CNC workshops running standard single-station vises, spindle utilisation is lower than it needs to be. Not because the machine is slow, and not because the programs are inefficient — but because the workholding strategy is the bottleneck.
This article explains how to systematically increase CNC machine output by upgrading your workholding strategy. It covers three specific approaches: the ZQ83 Double Action Dual-Station Vise for doubling parts-per-cycle, GT modular multi-vise arrays for maximising table utilisation, and the GT Quick-Change Jaw System for eliminating jaw changeover downtime. Each approach addresses a different source of lost spindle time, and they can be combined for compounding productivity gains.
All vise configurations described in this article are manufactured by Zhenghao from 20CrMnTi alloy steel, hardened to HRC 58–62, and precision-ground to 0.005 mm squareness and parallelism — ensuring that productivity gains are achieved without any compromise to part accuracy.
Before selecting a workholding upgrade, it is worth identifying precisely where production time is being lost. In a typical single-station vise setup on a VMC, non-cutting time breaks down into several categories:
Time Category | Typical Source | Recoverable? |
Part loading / unloading | Operator opens vise, removes finished part, loads new part, clamps | Partially — reduce with better workholding |
Jaw changeover | Unbolting and re-bolting jaw plates between part types | Largely — eliminate with quick-change system |
Vise re-alignment | Re-squaring vise after removal or jaw change | Largely — reduce with modular precision body |
Rapid traverse between parts | Spindle moving from one part to the next on the same table | Partially — reduce with denser workholding layout |
Single-part cycle | Machine cuts one part, stops, operator loads next | Largely — eliminate with dual-station or multi-vise |
Setup between jobs | Changing from one job to the next | Partially — reduce with standardised modular vises |
The three workholding strategies covered in this article directly address the largest recoverable sources of lost spindle time: single-part cycles, jaw changeover, and low table density.
A standard single-station vise holds one workpiece. The machine cuts that one part, the cycle ends, the operator opens the vise, removes the finished part, loads a new blank, clamps, and restarts the cycle. In a typical production scenario:
Cutting time per part: 3 minutes
Load / unload / clamp time: 1.5 minutes
Effective spindle utilisation: 3 ÷ 4.5 = 67%
That 33% of idle time is not recoverable with a faster program or a better cutting tool. It is a structural limitation of the single-station workholding approach.
The ZQ83 Double Action Precision Vise is built around a fundamentally different clamping architecture. Instead of one fixed jaw and one movable jaw, it features:
One fixed centre jaw — the rigid central reference
Two independent movable outer jaws — one on each side of the centre jaw
When the lead screw is turned, both outer jaws move inward simultaneously, clamping two workpieces against the central fixed jaw in a single operation. The result is two fully clamped, accurately positioned workpieces ready for machining — loaded and clamped in the same time it would take to clamp one.
With the same 3-minute cutting time per part and 1.5-minute load/unload time:
Single-station vise:
Cycle: 3 min cutting + 1.5 min loading = 4.5 min per part
Output: 13.3 parts per hour
ZQ83 Double Action Vise:
Cycle: 6 min cutting (2 parts) + 1.5 min loading (both parts simultaneously) = 7.5 min per 2 parts = 3.75 min per part
Output: 16 parts per hour
Improvement: +20% output from the same machine, same operator, same program
And this is a conservative estimate. In practice, the double action vise also reduces rapid traverse time between parts — because both parts are machined in a single program cycle without the spindle returning to home position between them — which further improves effective cutting time.
One of the most practically important features of the ZQ83 is its independent clamping action. The lead screw design allows the two outer jaws to clamp workpieces of slightly different sizes simultaneously, with equal clamping force applied to both.
In real production, raw material dimensions vary slightly from piece to piece — bar stock cut to length, castings with draft variation, or forgings with dimensional spread. A dual-station vise that requires both workpieces to be exactly the same size to clamp correctly would be impractical for most production environments. The ZQ83's independent clamping mechanism handles this variation automatically, ensuring both parts are held securely regardless of minor dimensional differences.
Both movable outer jaws of the ZQ83 incorporate Zhenghao's precision anti-lift pull-down mechanism. As clamping force is applied, the jaws are actively pulled slightly downward, pressing both workpieces firmly against the vise bed and preventing any upward lifting during heavy milling.
This is critical for production accuracy. Jaw lift — even of 0.01 mm — introduces a consistent dimensional error across every part in the batch. The anti-lift mechanism eliminates this error source, ensuring that both parts in every cycle are held at the correct Z-height.
Specification | Value |
Model | ZQ83150 / ZQ83150(I) |
Jaw width | 150 mm |
Clamping stations | 2 (dual station) |
Material | 20CrMnTi alloy steel |
Hardness | HRC 58–62 |
Squareness / parallelism | 0.005 mm / 100 mm |
Repeatability | 0.003 – 0.005 mm |
Jaw types available | Flat jaws, V-groove jaws, thread hole jaws |
Mounting | Horizontal or vertical; compatible with tombstone and pallet systems |
High-volume production of identical or similar parts — the primary use case
Parts with short-to-medium cycle times (under 10 minutes per part) where the load/unload proportion of total cycle time is significant
VMC production where the full table width can accommodate the dual-station footprint
HMC tombstone fixtures where the ZQ83 can be mounted on multiple faces of the tombstone for very high part density
Parts with slight dimensional variation in raw material — the independent clamping action handles this without operator intervention
View full specifications: ZQ83 Double Action Precision Vise
A standard VMC with a 600 × 400 mm table running a single 150 mm vise is using approximately 25% of its available table area for workholding. The remaining 75% of the table is empty — and the spindle spends a significant portion of each cycle in rapid traverse, moving from the part to tool change position and back.
By filling more of the table with workholding — and therefore with parts — you increase the number of parts cut per cycle, reduce the proportion of cycle time spent in rapid traverse, and reduce the frequency of operator intervention per part produced.
The GT precision modular vise is designed from the ground up for multi-vise array setups. The key enabling feature is the precision-ground body on all six sides.
Because every GT vise body is ground to 0.005 mm squareness and parallelism on all faces, multiple GT vises placed side-by-side on the machine table are automatically co-planar and co-linear. There is no need to individually align each vise in the array — the precision of the ground body ensures that all units share the same reference plane. This makes setting up a four-vise or six-vise array almost as fast as setting up a single vise.
Consider a VMC with a 700 mm × 400 mm table running GT150 vises (150 mm jaw width):
Single vise setup:
1 part per cycle
Rapid traverse: spindle moves from part to tool change and back — approximately 400 mm each way
Operator loads 1 part per cycle
4-vise array (2 × 2 configuration):
4 parts per cycle
Rapid traverse: spindle moves between adjacent vises — approximately 160 mm between parts
Operator loads 4 parts per cycle — but cycle time is 4× longer, so operator intervention frequency per part is reduced by 75%
Output increase: up to 3× improvement in parts per spindle hour (accounting for slightly longer rapid traverse within the array)
The GT series is available in jaw widths from 100 mm (GT100) to 300 mm (GT300), allowing the array density to be optimised for the specific part size and machine table dimensions.
Model | Jaw Width (B) | Height (H) | Clamping Force | Max Opening |
GT100 | 100 mm | 30 mm | 3,000 N | 100 mm |
GT125 | 125 mm | 40 mm | 3,000 N | 150 mm |
GT150 | 150 mm | 50 mm | 5,000 N | 200–400 mm |
GT175 | 175 mm | 60 mm | 6,000 N | 200–600 mm |
GT200 | 200 mm | 65 mm | 10,000 N | 200–600 mm |
GT300 | 300 mm | 80 mm | 12,000 N | 200–800 mm |
For multi-vise array planning, select the jaw width that best matches your part size. Smaller jaw widths (GT100, GT125) allow higher vise density on the table; larger jaw widths (GT200, GT300) provide higher clamping force for larger or heavier parts.
Linear array (single row):
Mount multiple GT vises in a single row along the X-axis. The spindle traverses the row in sequence, cutting all parts in a single program. This is the simplest configuration and is suitable for most VMC setups.
Grid array (multiple rows):
Mount GT vises in a 2×2, 2×3, or larger grid. This maximises table density but requires more careful program planning to ensure the spindle can access all parts without collision. Most suitable for shorter workpieces where the vise height does not restrict tool approach angles.
Tombstone array (HMC):
On horizontal machining centres with pallet systems, mount GT vises on multiple faces of a tombstone fixture. The HMC's rotary pallet allows the spindle to access all faces in a single cycle, achieving very high part density per pallet load. This is the highest-productivity configuration available for production CNC machining.
In a multi-vise array, all vises in the array should use the same jaw type to ensure consistent workpiece positioning across all stations. For production arrays, the most common choices are:
Flat jaws for pre-machined or consistent raw material
Step jaws for consistent part height positioning without parallel bars — particularly valuable in arrays where loading speed matters
Lattice / serrated jaws for raw stock in heavy roughing arrays
For guidance on selecting the right jaw type for your array, see the complete GT vise jaw selection guide.
For maximum output, the ZQ83 Double Action Vise can itself be used in a multi-vise array. Two ZQ83 units mounted side-by-side on a VMC table provide four clamping stations in a compact footprint — doubling the output of a two-vise standard array while maintaining the same table space.
This combination is particularly effective for high-volume production of small-to-medium parts where the part cycle time is short and operator loading frequency is the primary constraint.
In high-mix production environments — job shops, prototype facilities, and workshops handling multiple part numbers per shift — jaw changeover is a significant and often underestimated source of downtime.
A conventional jaw plate change requires:
Locating and retrieving the correct jaw plates from storage
Removing the existing jaw plates (unbolting 2–4 screws per jaw, per vise)
Cleaning the jaw mounting interface (chip contamination in threaded holes is common)
Installing the new jaw plates and torquing to specification
Verifying jaw seating and alignment
For a single vise, this process takes 5 to 15 minutes depending on chip contamination and accessibility. For a multi-vise array, multiply accordingly. In a workshop that changes jaw types 3–4 times per shift across multiple machines, this represents 1–2 hours of lost spindle time per machine per day.
The GT Precision Modular Vise with Quick-Change Jaw System replaces the conventional bolt-on jaw interface with a precision dovetail or wedge-lock mechanism. Jaw plates slide into the locking mechanism and are secured with a single wrench turn — no bolts to remove, no chip traps in threaded holes, no re-torquing required.
Jaw changeover time with the quick-change system: under 10 seconds per jaw set.
For a four-vise array changing jaw types three times per shift, this reduces jaw changeover time from approximately 60–90 minutes to under 5 minutes — recovering an hour or more of spindle time per shift.
Each GT Quick-Change Jaw Vise includes a pair of aluminum soft jaws as standard. Aluminum soft jaws serve two purposes:
Surface protection for delicate workpieces: Aluminum is softer than most workpiece materials, so it will not mark or damage finished surfaces during clamping
Custom profile machining: The soft jaw face can be machined to match the exact profile of a complex workpiece, providing full-contact clamping that distributes clamping force evenly and eliminates the risk of distortion
In a quick-change system, switching between hard jaws for roughing and soft jaws for finishing — or between different soft jaw profiles for different part numbers — takes seconds rather than minutes.
Model | Jaw Width | Clamping Length |
GT150×200 | 150 mm | 200 mm |
GT150×300 | 150 mm | 300 mm |
The GT150×300 configuration is particularly well-suited to multi-vise array setups where longer clamping length allows larger parts or multiple small parts to be held in a single vise station.
View full specifications: GT Quick-Change Jaw Vise
The three strategies described above are not mutually exclusive. They address different sources of lost spindle time and can be combined for compounding productivity gains.
Machine: VMC with 700 × 500 mm table
Part: Small aluminium bracket, 45 mm × 30 mm × 20 mm, 4-minute cycle time
Shift: 8 hours, 3 jaw type changes per shift (roughing → semi-finishing → finishing)
Baseline configuration (single standard vise, conventional jaws):
1 part per cycle
4 min cutting + 1.5 min loading = 5.5 min per part
3 jaw changes × 15 min = 45 min downtime per shift
Effective production time: 480 − 45 = 435 min
Parts per shift: 435 ÷ 5.5 = 79 parts
Upgraded configuration (2× ZQ83 double action vises in array + quick-change jaw system):
4 parts per cycle (2 vises × 2 stations each)
8 min cutting (4 parts) + 2 min loading (all 4 simultaneously) = 10 min per 4 parts = 2.5 min per part
3 jaw changes × 0.5 min (quick-change) = 1.5 min downtime per shift
Effective production time: 480 − 1.5 = 478.5 min
Parts per shift: 478.5 ÷ 2.5 = 191 parts
Output improvement: +142% from the same machine, same operator, same 8-hour shift.
This is not a theoretical maximum — it is a realistic estimate based on the documented performance characteristics of the ZQ83 dual-station vise and the GT quick-change jaw system.
Not every workshop needs all three strategies simultaneously. Use this guide to identify which approach delivers the highest return for your specific situation:
Production Scenario | Recommended Strategy | Expected Gain |
High-volume, single part number, short cycle time | ZQ83 Double Action Vise | +20–40% output per machine |
High-volume, single part number, medium-to-long cycle time | GT Multi-Vise Array | +50–200% output per machine |
High-mix, frequent jaw changes, multiple part numbers per shift | GT Quick-Change Jaw System | Recover 1–2 hrs spindle time per shift |
Maximum output, high-volume, multiple part numbers | ZQ83 array + Quick-Change | +100–200% output per machine |
Large or long workpieces, single part per cycle | Enables parts previously requiring custom fixturing | |
HMC tombstone production | GT array or ZQ83 array on tombstone faces | Maximum parts per pallet load |
A common concern when moving from a single-vise to a multi-vise or dual-station setup is whether the additional complexity introduces accuracy variation between stations. With Zhenghao GT series vises, it does not — and the reason is the manufacturing standard.
Every GT series vise body — whether a standard GT modular vise, a ZQ83 double action vise, or a quick-change jaw vise — is manufactured from 20CrMnTi alloy steel, hardened to HRC 58–62, and precision-ground to 0.005 mm squareness and parallelism on all critical surfaces.
This means:
Every station in a multi-vise array holds parts to the same 0.005 mm standard — there is no accuracy penalty for using multiple vises
Both stations in a ZQ83 dual-station vise hold parts to the same standard — parts from station 1 and station 2 are dimensionally interchangeable
Jaw changes on the quick-change system do not require re-qualification — the precision dovetail interface maintains the 0.005 mm standard after every jaw swap
Productivity and precision are not in conflict. The GT series is designed to deliver both simultaneously.
Before configuring a multi-vise array or dual-station setup, work through these planning points:
Confirm the usable table area and T-slot spacing. Calculate how many vises of your chosen jaw width can be mounted within the usable area, accounting for the vise body length (L dimension) and any required clearance between vises.
Verify that the spindle can reach all workpiece positions in the array without collision. In a grid array, confirm that the tool can access the workpieces in the inner positions without the spindle head contacting the outer vises.
For a multi-vise array, the CNC program must include all part positions as separate work coordinate systems (WCS). Most modern CNC controllers support multiple WCS offsets (G54, G55, G56, G57, etc.) — use one WCS per vise station. For a 4-station array, you need 4 WCS offsets.
In a dual-station or multi-vise setup, the operator loads all stations before the cycle starts and unloads all stations after the cycle ends. Ensure that the total cycle time (cutting time × number of stations) is long enough to allow the operator to comfortably load and unload all stations between cycles. If the cycle is very short, the operator may become the bottleneck rather than the machine.
All stations in an array should use the same jaw type to ensure consistent workpiece positioning. If different jaw types are needed for different operations, use the quick-change jaw system to switch all vises simultaneously between operations.
In high-output multi-vise setups, maintenance frequency increases proportionally with the number of stations. Key maintenance points:
Clean all vise beds between cycles — in a 4-station array, this means cleaning 4 vise beds before each load. Establish a standard cleaning routine as part of the operator cycle.
Check lead screw lubrication at the start of each shift — apply a small amount of machine oil to the lead screw thread on each vise. In high-cycle production, lead screws wear faster than in low-volume use.
Inspect jaw faces weekly — in high-volume production, jaw face wear accumulates faster. Replace jaw plates when wear is visible or clamping performance deteriorates.
Re-verify array alignment weekly — vibration from high-volume production can gradually shift vise positions. Re-check dial indicator TIR across the array weekly and re-align if necessary.
Check mounting bolt torque at the start of each shift — high-cycle vibration loosens mounting bolts over time. Re-torque if any movement is detected.
The workholding strategy is the single most accessible lever for increasing CNC machine output without capital investment in new machines. A double action dual-station vise, a modular multi-vise array, and a quick-change jaw system each address a specific and recoverable source of lost spindle time — and together, they can more than double the output of a standard VMC running a single conventional vise.
The Zhenghao GT series provides all three strategies within a single, compatible product family:
ZQ83 Double Action Dual-Station Vise — two clamping stations, one lead screw operation, double parts per cycle
GT Standard Modular Vise with Interchangeable Jaws — precision-ground modular body for fast, accurate multi-vise array setup
GT Quick-Change Jaw Vise — jaw changeover in seconds, not minutes, for high-mix production
ZQ84 Two-Piece Vise — unlimited clamping capacity for oversized workpieces
All manufactured from 20CrMnTi alloy steel, hardened to HRC 58–62, precision-ground to 0.005 mm — delivering maximum output without any compromise to part accuracy.
For bulk orders, multi-vise configuration advice, or OEM inquiries, contact us at zhjx@pyzhjx.com or +86-18660185316.
In a typical production scenario with a 3–5 minute part cycle time and 1–2 minute load/unload time, switching from a single-station vise to a ZQ83 double action vise increases output by 15–25% from the same machine and operator. The gain is higher for shorter cycle times (where load/unload is a larger proportion of total cycle time) and lower for longer cycle times.
Yes, within limits. The ZQ83's independent clamping action allows the two outer jaws to clamp workpieces of different sizes simultaneously. However, both parts must fit within the jaw width (150 mm for the ZQ83150) and must be compatible with the same jaw type. For parts requiring very different jaw types, use two separate standard vises with quick-change jaws instead.
This depends on your machine table dimensions and the jaw width of the vises. As a general guide, a 600 × 400 mm VMC table can accommodate 2–4 GT150 vises in a linear array, or 4–6 GT100 vises. A 700 × 500 mm table can accommodate 3–6 GT150 vises or 6–9 GT100 vises. Always verify spindle travel and tool clearance before finalising the array configuration.
No — provided all vises are correctly aligned and the same jaw type is used across all stations. Because all GT series vise bodies are precision-ground to 0.005 mm on all six sides, a correctly set up multi-vise array holds all parts to the same accuracy standard as a single vise. Parts from different stations in the array are dimensionally interchangeable.
Using the GT Quick-Change Jaw System, all four vises in an array can have their jaw plates changed in under 2 minutes — approximately 10 seconds per jaw set per vise. With conventional bolt-on jaws, the same operation would take 20–40 minutes. For high-mix production where jaw types change multiple times per shift, the quick-change system is the most impactful single upgrade available.
Yes. The ZQ83 can be mounted horizontally or vertically and is fully compatible with tombstone and pallet fixture systems on horizontal machining centres. Mounting ZQ83 vises on multiple faces of a tombstone provides very high part density per pallet load, making it one of the most productive workholding configurations available for HMC production.
