The Koike Aronson LD4 is a compact benchtop welding positioner that tilts from 0 to 105° across 8 fixed positions, handles up to 400 lb, and delivers a 300-amp rotary ground for MIG and TIG welding of small weldments and pipe flanges.
Engineered and manufactured by Aronson craftsmen in the USA, the LD4 Portable Benchtop Positioner sets the standard for build quality and performance in its class. Designed for smaller weldments — including pipe flanges with the optional 3-jaw chuck — it pairs precise, repeatable rotation with rugged worm-gear durability. Its drive holds a steady rotation speed under maximum load and resists TIG welding interference.
More than a welding positioner, the LD4 doubles as a smooth, controlled turntable for precision assembly and part positioning. In fabrication shops, pipe-welding training centers, and welding schools, it provides the controlled movement, repeatability, and toughness serious professionals demand.
Key Features
- 8 Fixed Tilting Positions: Tilt from 0 to 105° in 15° increments for repeatable, hands-free angle setup.
- Self-Locking Worm Gear Drive: The manual tilt gearbox locks the tilt angle for maximum stability while welding.
- Variable Speed, 0.25–6.5 RPM: A simple control interface sets rotation speed and direction.
- 300 A Rotary Ground: A 300-amp rotary ground connection keeps current flowing cleanly through full rotation.
- MIG & TIG Ready: 3/8" NPT tapped thru-holes at each end of the shaft accept inert shielding-gas connections.
- 20-1/2" Worktable: Four 9/16" slots for fast fixture setup, 3/8" thru-holes for equipment passthrough, and up to 18" maximum clamping diameter.
- Momentary Foot Switch: Rotates continuously at the set speed and direction until you lift your foot, on an 8 ft cord, so both hands stay on the torch.
- Optional 3-Jaw Self-Centering Chuck: Three sizes (WP-200, WP-300, WP-400) mount to the table's integrated tapped holes; a fully enclosed faceplate protects against flux and weld spatter.
View full specifications, comparison & FAQ
Specifications
| Specification | Detail |
|---|---|
| Type | Benchtop tilting/rotating welding positioner |
| Rated Load Capacity | 400 lb |
| Table Size | 20-1/2" diameter, 1/2" thick |
| Maximum Clamping Diameter | 18" |
| Table Slots | (4) 9/16" wide |
| Thru-Hole | 3/8" |
| Rotation Speed | 0.25–6.5 RPM, variable |
| Tilt Range | 0° to 105° in 15° increments (8 fixed positions) |
| Tilt Mechanism | Manual tilt gearbox, self-locking worm gear drive |
| Welding Ground | 300 A rotary ground |
| Shielding Gas Ports | 3/8" NPT tapped thru-holes at each shaft end |
| Primary Voltage | 115 V |
| Controls | Speed and rotation-direction controls; momentary foot switch with 8 ft cord |
| Table Flat Height | 16-1/2" |
| Tilt Centerline Height | 13-7/8" |
| Overall Machine Size (W × L × H) | 28-15/32" × 15-9/32" × 28" |
| Base (L × W) | 15" × 22", 13/32" tie-down holes |
| Shipping Weight | 185 lb |
| Welding Processes | MIG and TIG |
| Optional Chuck | 3-jaw self-centering chuck: WP-200, WP-300 or WP-400, enclosed faceplate |
| Warranty | 24 months from date of shipment (Koike Aronson Standard Warranty) |
| Made In | USA, by Koike Aronson, Arcade, NY |
| SKU / Part Number | LD0000 |
Specifications from the LD4 brochure, which includes the full dimensional drawing. Specifications are subject to change without notice.
Chuck Sizing Options
| Chuck | Inside Clamp Range | Outside Clamp Range | Weight |
|---|---|---|---|
| WP-200 | 3.1"–8.7" | 0.8"–5.1" | 13 lb |
| WP-300 | 4.7"–11.8" | 2.0"–7.9" | 26 lb |
| WP-400 | 6.5"–15" | 3.5"–12.2" | 48 lb |
Best For
- Welding pipe flanges (with the optional 3-jaw chuck)
- Small weldments and sub-assemblies
- Pipe-welding training centers and welding schools
- Fabrication shop precision assembly
- Field and small-workshop work where a compact footprint matters
- General part positioning as a controlled turntable
How the LD4 Compares to Other Benchtop Positioners
| Model | Rated Capacity | Tilt Range | Rotation Speed | Table | Ground | Chuck Options | Manufacturer |
|---|---|---|---|---|---|---|---|
| Koike LD4 | 400 lb | 0–105° (8 positions) | 0.25–6.5 RPM | 20-1/2" | 300 A | WP-200 / WP-300 / WP-400, enclosed faceplate | Koike Aronson, Arcade, NY |
| MAC PS-1F | 200 lb flat; 100 lb vertical at 2" CG | 0–90° | 0.3–5 RPM | 12" | 500 A | MT6 or WP200 | All-Fab Corp., Michigan |
| MAC PS-2F | 550 lb flat; 325 lb vertical at 4" CG | 0–90° | 0.3–5 RPM | 14" | 500 A | MT10 or WP-300 | All-Fab Corp., Michigan |
| Key Plant VP0.05 | 220 lb horizontal; 110 lb vertical | 135° | 0.3–5 RPM | 11.8" | 500 A | None listed | Key Plant Automation, UK |
Competitor figures are taken from each manufacturer's published specifications as of September 2026.
Frequently Asked Questions
What is the Koike LD4 welding positioner?
The Koike Aronson LD4 is a compact benchtop welding positioner that tilts from 0 to 105° across 8 fixed positions and provides a 300-amp rotary ground for MIG and TIG welding of small weldments and pipe flanges. It is built in the USA by Koike Aronson.
How far does the LD4 tilt?
The LD4 tilts from 0 to 105° in 15° increments, giving 8 fixed tilting positions. A self-locking worm gear drive holds the selected angle securely while you weld.
What is the load capacity of the LD4 positioner?
The LD4 has a rated load capacity of 400 lb, making it well suited to small weldments, pipe flanges, and precision sub-assemblies on the benchtop.
How big a part will the LD4 hold?
The LD4 has a 20-1/2" table with four 9/16" slots and an 18" maximum clamping diameter. With the optional chucks, the WP-200 clamps 0.8"–8.7", the WP-300 clamps 2.0"–11.8", and the WP-400 clamps 3.5"–15", across their inside and outside clamp ranges.
How fast does the LD4 rotate?
Rotation speed is variable from 0.25 to 6.5 RPM, and the drive holds a steady speed under maximum load.
Can the LD4 weld pipe flanges?
Yes. The optional 3-jaw self-centering chuck (WP-200, WP-300 or WP-400) mounts to the table's integrated tapped holes and holds pipe and flanges securely, with a fully enclosed faceplate that protects against flux and weld spatter.
Is the LD4 compatible with MIG and TIG welding?
Yes. The LD4 is MIG- and TIG-ready, with a 300-amp rotary ground connection and 3/8" NPT tapped thru-holes at each end of the shaft for inert shielding-gas connections. Its drive is built to resist TIG welding interference.
What power does the LD4 need?
The LD4 runs on 115 V standard primary voltage.
Where is the Koike LD4 made?
The LD4 is engineered and manufactured in the USA by Koike Aronson, built by the same Aronson craftsmen behind the company’s larger industrial positioners.
What warranty comes with the LD4?
The LD4 is covered by the Koike Aronson Standard Warranty: 24 months from the date of shipment against functional defects in materials and workmanship, for the first buyer of new equipment purchased from Koike Aronson or an authorized dealer.
Who is the LD4 positioner best for?
It suits fabrication shops, pipe-welding training centers, welding schools, and precision-assembly work — anywhere you need controlled, repeatable rotation and tilting for smaller weldments in a compact footprint.
What controls and accessories are included?
The LD4 includes speed and rotation-direction controls, a momentary foot switch on an 8 ft cord for hands-free operation, and a 20-1/2" worktable with four 9/16" slots for fast fixture setup. The 3-jaw self-centering chuck is available as an option in three sizes.
24-month Koike Aronson Standard Warranty. New equipment is warranted free from functional defects in materials and workmanship for twenty-four (24) months from the date of shipment, for the first buyer of equipment purchased from Koike Aronson or an authorized dealer, when properly installed, operated under normal use and maintained as recommended. Expendable parts are warranted only at the time of shipment, and components not manufactured by Koike Aronson carry their original manufacturer’s warranty. Read the full Standard Warranty (Form SF-01).
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Great benchtop table
This table was a rock solid investment, we will be ordering more soon
