Spectra Precision M402 Batterboard Clamp

Mount Your Instrument. Hold Your Grade. Move Fast.

The Spectra Precision M402 Batterboard Clamp is built for contractors who can't afford setup delays on active job sites. Whether you're running a grade laser across a foundation dig or setting elevations with a theodolite, the M402 lets you lock your instrument onto a wood or steel batterboard in seconds—without sacrificing stability or accuracy. This is the kind of hardware that earns its place in a crew's daily kit.

Overview & Jobsite Applications

The M402 is designed for use on batterboards—the temporary horizontal reference boards set up at corners and offsets during site layout. These boards take a beating on real job sites, and the M402's heavy-duty construction is built to match. The universal 5/8x11 threaded mounting plate accommodates virtually any standard surveying or grade laser instrument, allowing crews to swap tools between stations without re-leveling from scratch. Accommodating boards up to 2.17 inches (55mm) thick, the M402 works on standard dimensional lumber, engineered boards, and light steel framing used in modern site layout.

Key Specifications

• Model: Spectra Precision M402
• Mount Thread: 5/8 x 11 standard instrument thread
• Maximum Board Thickness: 2.17 in (55mm)
• Compatible Instruments: Grade lasers, pipe lasers, theodolites, and optical levels with 5/8x11 base
• Board Compatibility: Wood batterboards and light steel framing members
• Construction: Heavy-duty clamping mechanism for secure grip under field conditions

Key Features

• Universal 5/8x11 Mounting Plate: Accepts virtually all standard surveying instruments right out of the box—no adapters required for most setups
• Quick-Release Clamping: Designed for fast instrument changes between batterboard stations, saving time on multi-point layout jobs
• Wide Board Capacity: Grips boards up to 55mm thick, covering standard 2x lumber as well as thicker engineered wood
• Heavy-Duty Build: Rugged construction stands up to the rough handling and environmental exposure typical of foundation and site layout work
• Stable Platform: Clamp holds the instrument level and secure, minimizing the chance of disturbing a critical grade shot when moving between positions

Job Applications

Foundation Layout: Set your grade laser or optical level on the M402 at each batterboard corner to establish consistent elevation benchmarks across a foundation pour site. Swap the instrument between stations without resetting grade each time.

Utility Trenching: Mount a pipe laser or grade laser on a batterboard clamp over a trench to establish consistent invert elevations. The M402's secure grip ensures the instrument doesn't shift as crews work around it.

Site Preparation & Rough Grading: During rough grading operations, batterboard setups help operators hit target elevations quickly. The M402 keeps the reference instrument locked in place through equipment vibration and foot traffic nearby.

Commercial Framing Layout: On commercial sites where steel batterboards or engineered lumber are used as reference stakes, the M402's wide throat accommodates non-standard board thicknesses that other clamps can't handle.

Compatible Accessories

• Spectra Precision HV302 Horizontal/Vertical Laser
• Spectra Precision GL422N Grade Laser
• 5/8x11 Tribrach Adapter
• Spectra Precision Tripod & Grade Rod Combo
• Laser Receiver for Grade Lasers

Related Guides

• How to Set Up Batterboards for Foundation Layout
• Choosing the Right Instrument Mount for Your Job Site
• Grade Laser vs. Theodolite: Which Tool Do You Need?
• Site Layout Best Practices for Residential & Commercial Construction

Frequently Asked Questions

What instruments are compatible with the Spectra Precision M402?

The M402 accepts any instrument with a standard 5/8x11 threaded base, which includes most grade lasers, pipe lasers, theodolites, and optical levels from Spectra Precision and other major manufacturers.

What is the maximum board thickness the M402 can clamp onto?

The M402 accommodates boards up to 2.17 inches (55mm) thick, making it suitable for standard 2x dimensional lumber, thicker engineered boards, and light steel framing used in site layout applications.

Can the M402 be used on steel batterboards?

Yes. The M402's clamping mechanism is designed to grip both wood and light steel framing members, giving it flexibility for modern job sites that use metal framing for temporary reference structures.

Will using the M402 to swap instruments between stations affect my grade accuracy?

The M402's quick-release design allows the instrument to be removed and reinstalled without disturbing the clamp's position on the board. However, as with any instrument move, it is best practice to verify your level and grade shot each time you reattach the instrument to a new station.