tool materials

MATERIAL RELATED TO MAKING OF TOOLS AND

FIXTURES

CNC K05-04-05

DIDALAM MEREKABENTUK JIGS DAN FIXTURES TOOL DESIGNER BERTANGGUNGJAWAB DIDALAM MEMILIH BAHAN YANG SESUAI DIGUNAKAN UNTUK MEMBINANYA.

ADAPTABILITY(kesesuaian), DURABILITY(tahan lasak) AND ECONOMY MESTI DIAMBIL KIRA SEBELUM SESUATU BAHAN ITU DIPILIH UNTUK SESUATU TOOL.

PROPERTIES OF TOOL MATERIALS

MENERANGKAN MENGENAI BAHAN YANG DIGUNAKAN

AKAN BEREAKSI/BERKELAKUAN (BEHAVIOR) BILAMANA

IANYA DIGUNAKAN.Go to the strength

of material notes

PROPERTIES• HARDNESS

• TOUGHNESS

• WEAR RESISTANCE

• MACHINABILITY

• BRITTLESNESS

• TENSILE STRENGTH

• SHEAR STRENGTH

HARDNESSTHE ABILITY OF A MATERIAL OF A

MATERIAL TO RESIST PENETRATION OR INDENTATION.IT IS ALSO A MEANS TO MEASURE ONE MATERIAL AGAINTS ANOTHER.NORMALLY, THE HARDER THE MATERIAL THE GREATER ITS TENSILE STRENGTH.

TOUGHNESS

THE ABILITY OF A MATERIAL TO ABSORB SUDDEN APPLIED LOADS OR SHOCKS REPEATEDLY WITHOUT PERMANENT DEFORMATION.

WEAR RESISTANCE THE ABILITY OF A MATERIAL TO

RESIST(MENAHAN) ABRASION(BAHAGIAN LUAR

SEKALI) EITHER BY NON-METALLIC MATERIAL OR BY CONSTANT CONTACT WITH A MATERIAL OF EQUAL HARDNESS. HARDNESS IS ALSO A PRIME FACTOR IN WEAR RESISTANCE . USUALLY WEAR RESISTANCE INCREASES WITH HARDNESS.

MACHINABILITY

THE MEASURE OF HOW WELL A MATERIAL CAN

BE MACHINED. FACTORS CONCERNING

MACHINABILITY ARE CUTTING SPEED, TOOL

LIFE AND SURFACE FINISH.

BRITTLENESS

• THE OPPOSITE OF TOUGHNESS. BRITTLE MATERIALS HAVE TENDENCY TO FRACTURE WHEN SUDDEN LOADS ARE APPLIED. MATERIALS THAT ARE VERY HARD, FOR THE MOST PART, ARE ALSO VERY BRITTLE

TENSILE STRENGTH

•THE MEASURE OF A MATERIAL’S RESISTANCE TO BEING PULLED APART. IT IS THE PRIMARY TEST USED TO DETERMINE THE STRENGTH OF MATERIAL. TENSILE STRENGTH INCREASE PROPORTIONALLY WITH HARDNESS.

SHEAR STRENGTH

•THE MEASURE OF A MATERIAL’S RESISTANCE TO FORCES APPLIED IN OPPOSITE AND PARALLEL DIRECTIONS. SHEAR STRENGTH IS APPROXIMATELY 60 % OF TENSILE STRENGTH.

FERROUS TOOL MATERIALS

• INCLUDE CAST IRON, CARBON STEEL, ALLOY STEEL, AND TOOL STEEL. THESE METALS HAVE A BASE OF IRON. FERROUS METALS MAKE UP THE LARGEST GROUP OF TOOL MATERIAL IN COMMON USE.

CAST IRON•USED FOR TOOL BODIES AND SOME COMMERCIAL JIG AND FIXTURE COMPONENT.

•BEFORE CAST TOOL BODY CAN BE USED, IT MUST BE MADE INTO A PATTERN AND THEN A MOLD AND YTHEN POURED.

CARBON STEEL•CARBON STEEL IS THE PRIMARY MATERIAL OF JIG AND FIXTURE TOOLING. ITS EASE OF FABRICATION, LOW COST, AVAILABILITY, AND VERSATILITY HAVE MADE IT POPULAR FOR TOOL CONSTRUCTION.

LOW CARBON STEEL – USED MAINLY FOR STRUCTURAL PARTS OF A JIG OR FIXTURE.

MEDIUM CARBON STEEL – USED IN MUCH THE SAME WAY AS LOW CARBON STEEL, BUT IN AREAS OF TOOLING THAT REQUIRE MORE STRENGTH. EXAMPLE LIKE A CLAMPS,STUDS, NUTS, AND IN ALMOST ANY AREA WHERE TOUGHNESS IS REQUIRED.

•CARBON CONTENT FOR MEDIUM CARBON STEEL IS BETWEEN 0.30 % AND 0.50%.

•MEDIUM CARBON STEEL IS MORE DIFFICULT TO MACHINE, CASE-HARDEN AND WELD THAN LOW CARBON STEEL.

•HIGH CARBON STEEL – GENERALLY LIMITED TO TOOL CONSTRUCTION IN AREAS THAT ARE SUBJECT TO THE MOST WEAR. PART SUCH AS DRILL BUSHINGS, LOCATORS, WEAR PADS, AND SUPPORTS CAN BE MADE OF THIS MATERIAL.

•CARBON CONTENT BETWEEN 0.50% AND 2.0%

ALLOY STEELS•ARE ARE NOT GENERALLY USED

FOR TOOL CONSTRUCTION BECAUSE OF THEIR ADDED COST.

•ALLOYING ELEMENTS ARE ELEMENTS THAT, WHEN ADDED TO A MATERIAL, CHANGE OR MODIFY THE MATERIAL AND BRING ABOUT A PREDICTABLE CHANGE IN ITS PROPERTIES.

THE MOST COMMON ALLOYING ELEMENTS AND THEIR EFFECTS

ARE :• CARBON – MAIN HARDENING

ELEMENT• SULFUR – EASIER MACHINING• PHOSPHORUS – EASIER MACHINING• MANGANESE – CONTROLS SULFURS

EFFECT; INCREASE HARDNESS• NICKEL – TOUGHNESS• CHROMIUM – CORROSION

RESISTANCE (OVER 15% CHROMIUM); DEPTH HARDNESS (LESS THAN 15% CHROMIUM)