Manhole Cover Type B

Model	Nominal Size	L₁	L₂	L₃	B₁	B₂	B₃	S	Fastener		Weight(kg)
									Diameter	Quentity
B₁	450×350	450	470	570	350	370	470	4	M20	16	28.9
								6			33.8
								8			37.2
								10			41.2
	600×400	600	620	720	400	420	520	8		20	49.5
								10			55.6
								12			61.2
								14			67.6
	800×600	800	820	920	600	620	720	12		26	67.2
								14			75.2
								16			82.8
								18			89.9
B₂	800×400（椭圆形）（Oval ）	800	830	930	400	430	530	12		24	56.8
								14			63.2
								16			69.2
								18			76.2
Stub is stainless steel SUS304,nut material could be steel、brass、stainless steel、as user’s option.