Which Explosion-Proof Level Is Higher, T4 or T6

T6 is the highest grade available.

Temperature Class IEC/EN/GB 3836	Maximum Surface Temperature of Equipment T [°C]	Ignition Temperature of Combustible Substances [°C]
T1	450	T＞450
T2	300	450≥T＞300
T3	200	300≥T＞200
T4	135	200≥T＞135
T5	100	135≥T＞100
T6	85	100≥T＞8

The ‘T’ stands for temperature rating, reflecting the critical temperature for gas explosions in an environment. For instance, if the explosion temperature of a flammable gas is 150°C, then explosion-proof products with ratings of T4, T5, or T6 must be chosen.

With a maximum temperature limit of 85°C, T6 is considered the best and safest option and can serve as a replacement for other products.