Quick Answer: The Plotting Compass, Superior is a plotting compass with a non-magnetic aluminium/brass housing and glass crystal, made in 20mm or 50mm diameter. Its air-damped carbon steel needle turns on an agate-jewelled bearing.
Last updated: October 2026
Key Features
Non-magnetic aluminium/brass alloy housing
Clear glass crystal
Hardened carbon steel needle, cobalt-treated
Agate-jewelled pivot bearing
Air damping so the needle settles quickly
20mm or 50mm diameter
Technical Specifications
Specification
Value
Housing
Non-magnetic aluminium/brass alloy, glass crystal
Needle
Hardened carbon steel, cobalt-treated
Pivot
Agate-jewelled bearing
Damping
Air-damped
Diameter
20mm or 50mm
HS Code
9014.10.00
About This Product
Plotting compasses trace magnetic field lines around magnets and current-carrying conductors, one dot at a time. The jewelled pivot and air damping help the needle respond in weak fields and come to rest without long swinging.
Frequently Asked Questions
What sizes does the Superior plotting compass come in?
It is made in 20mm or 50mm diameter.
What is the housing made of?
A non-magnetic aluminium/brass alloy housing with a glass crystal.