Manhole Covers & Engineering Castings
Design - Cast - Supply
CAST IRON
DUCTILE IRON


Microstructure consists of graphite in the form of flakes which act as stress raisers.


Microstructure consists of graphite in the form of spheroids acts like crack arrestors.
Impact resistance is poor Under severe impact it will break.
Strong impact resistance. Under sevre impact it will bend.
  • Tensile strength is low
  • No elongation or Ductility
  • ISO 185 : 1985 Grade : 350 (Grey Cast Iron). Tensile Strength: 350 N / mm2 Min.
  • Elongation : Nil.
  • Tensile strength is high
  • Almost twice than cast iron
  • Moderate elongation & ductility
  • ISO 1083 : 1987 Grde : 500/7
  • Tensile Strength : 500 N / mm2 Min.
  • Elongation : 7% Min.
Due to lower strength, weight of the manhole covers will be more for a spec c duty.
Due to high strength, weight of the manhole covers will be less (Min. 2/3rd) by weight.
Due to higher weight handling will be dif cult.
Dut to low weight transportation, handling, installation and inspection is easy.
Poor capability of vibration absorption
High capability of vibration absorption

AS 3996 Table of Load Classification

Australia Loading Class
Typical Uses
Approximate Wheel Load
BSEN Loading Class
Application
A
10kN
Extra light duty
Footways and areas accwssible only to pedestrians & pedal cyclists

330kg

Class A 15kN
B
80kN
Light Duty
Footways that can be mounted by vehicle or livestock, and light tractor paths

2,670kg

-
C
150kN
Medium Duty
Mails and pedestrian areas open to slow moving commercial vehicles

5,000kg

Class B 125kN
D
210kN
Heavy Duty
Carriageways of roads and areas open to commercial vehicles

8,000kg

Class C 250kN
E
400kN
Extra Heavy Duty
General docks and aircraft pavements

13,700kg

Class D 400kN
F
600kN
Extra Heavy Duty
Docks and aircraft pavements subject to high wheel loads

20,000kg

Class E 600kN
G
900kN
Extra Heavy Duty
Docks and aircraft pavements subject to very high wheel loads

30,000kg

Class F 900kN