The WD&WL Magnetic Plumb Bob is a specialized tool designed for masons, fitters, and maintenance workers to visually measure and establish vertical alignment during construction. Featuring a high-strength magnetic base, it securely attaches to steel surfaces — freeing both hands and significantly improving work efficiency. Available in 300g and 400g weights with 3-meter and 6-meter high-strength nylon lines, the cord is fine yet tough, resistant to tangling, ensuring precise and stable readings. The precisely machined brass bob has an accurate center of gravity, guaranteeing a consistently true vertical line. Widely used in building construction, pipe installation, equipment commissioning, and renovation projects, this series is an essential tool for professional tradespeople.
The base features a built-in high-strength magnet that firmly attaches to steel pipes, steel beams, scaffolding, and other ferrous surfaces. No need to hold it manually — both hands are free for other tasks, significantly improving work efficiency and safety.
The bob is precision-machined from premium brass and dynamically balanced to ensure the center of gravity is exactly at the geometric center. This guarantees a consistently true vertical line when freely suspended, with reliable readings unaffected by deviation.
Made from high-strength braided nylon, the line is fine yet tough — resistant to stretching, abrasion, and tangling. Available in 3m and 6m lengths to accommodate vertical measurement needs at various heights.
The 300g lightweight version is ideal for indoor renovation, pipe installation, and other precision work; the 400g heavier version suits outdoor construction and high-rise vertical measurement where stronger wind resistance and stability are required.
Specifically designed for masons, fitters, and maintenance workers to meet vertical alignment needs in bricklaying, pipe installation, equipment positioning, and renovation construction. An essential item in every professional tradesperson’s toolbox.
| Item |
W60330 |
W60331 |
| Specification |
3m×300g |
6m×400g |
| Line Length |
3m |
6m |
| Bob Weight |
300g |
400g |
| Box Qty |
6pcs |
6pcs |
| Carton Qty |
36pcs |
36pcs |
| Net Weight |
0.44kg |
0.58kg |
| Gross Weight |
17.30kg |
23.00kg |
| Magnetic |
Strong Magnetic Base |
Strong Magnetic Base |
| Bob Material |
Brass |
Brass |
| Line Material |
High-Strength Nylon |
High-Strength Nylon |
- Masonry & Bricklaying: Checking verticality when laying brick or block walls to ensure walls remain plumb
- Pipe Installation: Vertical alignment for water supply, drainage, and heating pipe installation
- Equipment Installation & Commissioning: Vertical calibration of machine tools, pumps, towers, and other equipment
- Renovation Projects: Vertical reference lines for ceiling, partition wall, and door frame installation
- Building Construction: Verticality inspection of columns, formwork, and rebar
- Maintenance Work: Positioning reference during equipment and pipe maintenance
- Steel Structure Construction: Vertical alignment during steel column and beam installation
- Curtain Wall Installation: Verticality control for glass and stone curtain wall installation
WD&WL is a professional hand tool manufacturer with our own factory and comprehensive quality management system. Every process — from raw material procurement to finished product shipment — is strictly controlled to ensure consistent, reliable quality.
Each plumb bob is precision-turned and dynamically balanced, with center-of-gravity deviation controlled to minimal tolerance. This is the core guarantee of plumb accuracy and our commitment to product performance.
The built-in strong magnet securely attaches to steel surfaces, enabling one-hand positioning and significantly improving work efficiency. This is the key design feature that distinguishes professional plumb bobs from ordinary ones.
We support brand logo customization (laser engraving/silk-screen printing), packaging customization, and weight/line length specification customization. Our professional team will assist you in developing a branding solution to support your tool brand building.
We maintain ample stock for standard specifications with fast shipping after order confirmation. Large orders also come with clear delivery time commitments to keep your supply chain running smoothly.
Our experienced export team is well-versed in international trade processes with fluent English communication. From inquiry, sampling, ordering to shipment, we provide professional follow-up throughout — making your procurement hassle-free.
A: The main difference is that a magnetic plumb bob has a strong magnet at the base, allowing it to attach to steel pipes, beams, and other ferrous surfaces. This frees both hands during construction, unlike ordinary plumb bobs that require manual holding or clamping at the top. The magnetic design significantly improves work efficiency and safety.
A: The 300g version is suitable for indoor work and precision installation — lighter and more maneuverable. The 400g version is better for outdoor construction and high-rise measurement — heavier, more wind-resistant, and provides a more stable vertical line. Choose 300g for primarily indoor use, and 400g for outdoor or high-altitude work.
A: The 3m line is suitable for indoor renovation and pipe installation in spaces up to 3 meters high. The 6m line works for high-rise buildings and column construction requiring longer vertical lines. If your work height exceeds 6 meters, contact us for custom longer line options.
A: The bob is precision-machined from premium brass. Brass has high density (approximately 8.5 g/cm³), providing more weight per volume for better stability. Additionally, brass is corrosion-resistant, won’t rust, looks professional, and offers a long service life.
A: No. The magnetic base only serves to secure the plumb bob to a steel surface. Once freely suspended, the bob aligns vertically under gravity — the magnetic force does not affect the bob’s free swing or final resting position. Accuracy is guaranteed as long as the bob is allowed to hang freely during measurement.
A: We use high-strength braided nylon line with excellent tensile strength and abrasion resistance — not prone to breaking under normal use. The pairing of 300g with 3m line and 400g with 6m line is scientifically calculated, with line strength fully meeting the demands of corresponding bob weights. Under normal use, the line can last several years.
