The Spectra Precision C71 Magnetic Mount is the purpose-built accessory for contractors who need fast, reliable, hands-free positioning of their CR700 laser receiver on ferrous jobsite surfaces. Whether you're checking grades on steel I-beams, aligning HSS columns, setting pipe slope, or working around rebar cages on a concrete pour, the C71 snaps securely into position so you can work with both hands free and your grade reference locked in place.
Overview: Where the C71 Fits on the Job
Commercial steel erectors, mechanical contractors, and concrete placement crews consistently run into the same challenge — holding a laser receiver in one hand while trying to mark, measure, or make adjustments with the other. The C71 eliminates that compromise. Its industrial-strength magnetic base bonds instantly to any ferrous surface and holds the CR700 at the correct height and orientation without a rod holder, tripod, or secondary person. It's particularly effective in structural steel environments where conventional grade rods are impractical, and on pipe work where slope verification demands a stable, repeatable receiver position.
Key Specifications
- Compatible Receiver: Spectra Precision CR700
- Attachment Type: Industrial magnetic base
- Target Surfaces: Steel I-beams, HSS tubing, metal decking, pipe, rebar
- Mounting Interface: Secure clip mount designed for CR700 receiver body
- Build: Jobsite-rated housing, impact-resistant construction
- Manufacturer: Spectra Precision (Trimble)
- Part Number: C71
Key Features
- Strong permanent magnet provides instant, tool-free attachment to any ferrous surface
- Precision-fit CR700 receiver clip holds receiver securely without play or shifting
- Eliminates the need for a grade rod or rod holder when working on steel structures
- Allows one-person grade checks and layout tasks on structural steel, pipe, and rebar
- Compact, lightweight design — fits easily in a tool bag or vest pocket
- Complements the CR700's audible and visual grade indicators for fast positioning
- Durable enough for repeated use in commercial construction environments
Job Applications
Structural Steel Erection: Attach the CR700 directly to I-beams and HSS columns during steel erection to verify elevation and plumb without a rod holder. Speed up your workflow on multi-story commercial frames where carrying a grade rod is impractical.
Mechanical & Plumbing Pipe Work: Mount the CR700 to steel pipe runs to set and verify slope on gravity-fed drain lines, storm systems, and process piping. Maintain consistent grade across long runs with a fixed receiver reference point.
Metal Deck & Concrete Pours: Position the CR700 on metal decking or embedded rebar to monitor screed elevation during concrete placement. Keep your hands free for screeding, vibrating, and directing the pump operator.
Pre-Pour Rebar Inspection: Clamp to rebar cages for quick elevation checks during pre-pour inspections, confirming cover depth and top-of-rebar elevation against your laser plane before concrete is placed.
Compatible Accessories
- Spectra Precision CR700 Laser Receiver
- Spectra Precision HL760 Laser Receiver
- Spectra Precision HV301 Rotary Laser Level
- Spectra Precision LL300N Laser Level
- Grade Rod & Receiver Clamp Combo Kit
Related Guides
- How to Set Up the Spectra CR700 Receiver for Grade Checking
- Best Laser Receivers for Structural Steel Applications
- Rotary Laser Level Buyer's Guide for Commercial Contractors
- Setting Pipe Slope with a Rotary Laser and Remote Receiver
Frequently Asked Questions
- Will the C71 work with laser receivers other than the CR700?
- The C71 is specifically designed and fitted for the Spectra Precision CR700 receiver. The clip interface is matched to the CR700 body dimensions, so it will not provide a secure fit on other receiver models. If you're using a different Spectra or Trimble receiver, contact Express Tools to confirm the correct magnetic mount accessory for your model.
- Is the magnet strong enough to hold on vertical steel surfaces?
- Yes. The C71 uses an industrial-grade permanent magnet rated for secure attachment on vertical ferrous surfaces including the flanges of I-beams, HSS column faces, and steel pipe. It is designed to hold the CR700 securely during normal jobsite use, though it should not be used on surfaces with heavy vibration or impact without additional support.
- Does the C71 work on rebar or only flat steel surfaces?
- The C71 performs best on flat or gently curved ferrous surfaces such as beam flanges, pipe walls, and metal decking. On rebar, performance depends on the bar diameter and surface condition. Larger diameter rebar (#7 and above) with clean surface area generally provides adequate contact for the magnetic base. For best results on rebar applications, position the magnet across multiple bars where possible.
- Can I use the C71 with a Spectra rotary laser on a tripod at the same time?
- Absolutely — and this is the intended workflow. Set your Spectra rotary laser on a tripod at a known elevation, power up the CR700, attach it to the C71 magnetic mount, and fix the CR700 to your working surface. The CR700 will detect the rotating laser beam and give you continuous grade feedback via audible beeps and LED indicators while both your hands remain free for the task at hand.
Frequently Asked Questions
Will the C71 work with laser receivers other than the CR700?
The C71 is specifically designed and fitted for the Spectra Precision CR700 receiver. The clip interface is matched to the CR700 body dimensions, so it will not provide a secure fit on other receiver models. If you're using a different Spectra or Trimble receiver, contact Express Tools to confirm the correct magnetic mount accessory for your model.
Is the magnet strong enough to hold on vertical steel surfaces?
Yes. The C71 uses an industrial-grade permanent magnet rated for secure attachment on vertical ferrous surfaces including the flanges of I-beams, HSS column faces, and steel pipe. It is designed to hold the CR700 securely during normal jobsite use, though it should not be used on surfaces with heavy vibration or impact without additional support.
Does the C71 work on rebar or only flat steel surfaces?
The C71 performs best on flat or gently curved ferrous surfaces such as beam flanges, pipe walls, and metal decking. On rebar, performance depends on the bar diameter and surface condition. Larger diameter rebar (#7 and above) with clean surface area generally provides adequate contact for the magnetic base. For best results on rebar applications, position the magnet across multiple bars where possible.
Can I use the C71 with a Spectra rotary laser on a tripod at the same time?
Absolutely — and this is the intended workflow. Set your Spectra rotary laser on a tripod at a known elevation, power up the CR700, attach it to the C71 magnetic mount, and fix the CR700 to your working surface. The CR700 will detect the rotating laser beam and give you continuous grade feedback via audible beeps and LED indicators while both your hands remain free for the task at hand.