IOCL Junior Operator Fitter MCQ || IOCL Junior Operator General Science Questions and Answers

• Flexible hacksaw blades are designed to be flexible in the body to prevent breakage, especially when cutting curves.
• To achieve this, only the teeth of the blade are hardened, while the rest of the blade remains more flexible.

• The pitch of a hacksaw blade refers to the distance between the adjacent teeth on the blade.

• It’s a crucial factor in selecting the right blade for a specific cutting task.
• A smaller pitch (more teeth per inch) is used for harder materials, while a larger pitch (fewer teeth per inch) is used for softer materials

• The typical pitch of a coarse hacksaw blade is 1.8 mm.
• Coarse hacksaw blades have a larger distance between the teeth, which is referred to as the pitch.
• For coarse cutting tasks, especially on thick materials, a pitch of 1.8 mm is commonly used.
• This allows for faster cutting but results in rougher edges compared to blades with finer pitches.

• Fine Blade hacksaw has the smallest pitch?
• “Pitch” refers to the distance between teeth.
• A fine blade has more teeth per inch (TPI).
• Therefore, the distance between each tooth is smaller, resulting in a smaller pitch

• A hacksaw blade with a 1.0 mm to 1.4 mm pitch is classified as medium.
• Coarse blades have a pitch of 1.8 mm, while fine blades have a pitch of 0.8 mm

• A hacksaw blade specified as “300 x 1.8 mm pitch LA all-hard blade” indicates that the blade is 300 mm long and has a pitch of 1.8 mm.
• 300 Refers to the length of the blade in millimeters.
• 1.8 mm pitch: Indicates the distance between adjacent teeth on the blade.
• Based on the provided search results, 1.8 mm is considered a coarse pitch.

• The teeth on a hacksaw blade are set (bent) to the left and right, which creates a wider cut than the blade itself.
• This setting prevents the blade from binding in the material being cut, allowing for smoother operation and reducing the risk of the blade getting stuck or breaking during use.
• Imagine the hacksaw blade is trying to cut a path through wood or metal.
• If the blade was perfectly flat, it would get stuck easily because the sides of the cut would rub against the blade.

The two main types of hacksaw teeth settings are Staggered set and wave set.

These settings refer to how the teeth are bent to create a wider kerf (the slot cut by the saw) than the blade itself.

• Staggered Set: Alternate teeth are bent to the left and right, creating a clear path for chips to exit.
• Wave Set: Teeth are bent in a wave-like pattern, also aiding in chip removal and preventing binding.

The advantage of the staggered set on a hacksaw blade is it helps with chip clearance.

• Chip Clearance: In a staggered set, alternate teeth are bent to the left and right.
• This creates a wider kerf (the slot cut by the saw) than the blade itself.
• This wider kerf allows for better chip clearance, as the metal shavings produced during cutting have more space to escape.

• Hacksaw blades with a pitch of 0.8 mm are typically used for cutting hard materials like stainless steel or tool steel.
• For these applications, a wave set is the most common tooth configuration.
• The wave pattern helps to reduce vibration and chatter, resulting in a smoother and more controlled cut.