N42H vs N42SH: Engineering Comparison & Decision Guide

Key takeaways

N42H: 40–43 MGOe (318–342 kJ/m³); N42SH: 40–43 MGOe (318–342 kJ/m³), at 20°C.
N42H HcJ: ≥17 kOe (≥1353 kA/m); N42SH HcJ: ≥20 kOe (≥1592 kA/m), at 20°C.
The class temperature is a screening reference. Safe operation requires the material’s hot demagnetization curves, load line, opposing field and duty cycle.
BHmax is energy product. Differences do not give a fixed change in field, pull force, torque or required magnet volume.
Price and lead time require comparable quotations for the same geometry, coating, quantity and acceptance plan.
The listed 17 and 20 kOe HcJ minima are at 20°C. No hot HcJ value can be inferred here from the class rating or an approximate temperature coefficient.

Overview

N42H and N42SH are sintered NdFeB reference grades. They have the same listed energy-product range at 20°C. Compare remanence and intrinsic coercivity separately. These values describe the educational table; supplier specifications can differ. A design calculation or test is needed to compare output in the complete magnetic circuit.

Side-by-side

Side-by-Side Comparison

Reference properties and design questions. A count of comparison points does not establish a material or supplier recommendation.

Criterion	N42H	N42SH
BHmax at 20°C	40–43 MGOe (318–342 kJ/m³)	40–43 MGOe (318–342 kJ/m³)
Br at 20°C	12.9–13.3 kGs (1.29–1.33 T)	12.9–13.3 kGs (1.29–1.33 T)
HcJ minimum at 20°C	≥17 kOe (≥1353 kA/m)	≥20 kOe (≥1592 kA/m)
Nominal temperature class	120°C; geometry and load dependent	150°C; geometry and load dependent
Hot performance	Requires the proposed material’s hot curves	Requires the proposed material’s hot curves
Chemistry and processing	Confirm composition and route	Confirm composition and route
Price and availability	Quote for the actual part	Quote for the actual part

Confirm source conditions and the actual part requirements before using reference values as acceptance limits.

Use cases

Conditions for considering each option

When N42H wins

The N42H material meets the field and demagnetization requirements in the validated design.
Its part quotation and qualification plan fit the programme.

When N42SH wins

The N42SH material meets a requirement that the evaluated N42H material does not.
The measured benefit justifies any difference in part cost or qualification work.

How to choose

Decision Framework

Decision framework

Compare hot B-H and J-H curves at the worst working point, including faults and transient temperature. Then calculate or test output in the actual geometry. N42H and N42SH cannot be selected from the class temperature alone. Agree coating, acceptance tests and production route before comparing quotations.

Specs