Frequently Asked Questions (FAQs) for Machinery and Mold Machining

Jack Lie CNC machining expert

Specialize in CNC Milling, CNC Turning, 3D Printing, Urethane Casting, and Sheet Metal Fabrication Services.


  1. Define Drawing?

It precisely describes the shape, size, and technical requirements of the object.

  1. Define Projection?

An approach wherein a set of rays is passed through an object on an already known plane is called projection.

  1. Define Sectional View?

It is an image formed by the parallel rays of light passing through an object on the projection’s surface.

  1. Describe Three Fundamental Views of Object’s Projection?

The left view, front view, and top view

  1. How Would You Define Melting Point?

The temperature at which something starts converting into liquid form.

  1. What Do You Mean by Chemical Properties?

Chemical properties involve corrosion resistance and oxidation resistance.

  1. Define Antioxidant?

An antioxidant can be defined as an ability to avoid oxidation at any temperature.

  1. How Will You Define Corrosion Resistance?

The resistance offered by the substance against the attack of corrosion against any temperature

  1. Define Mechanical Property?

It is defined as an ability of a metal to withstand external stresses.

  1. What Are Some Mechanical Properties?

These properties include plasticity, fatigue, toughness, and hardness of the metal.

  1. How Do You Define Deformation?

The change in the size and shape of material under the impact of external forces

  1. What Are the Types of Deformation?

Deformation may be of certain types, like bending, stretch, distortion, sheer, and compression.

  1. Define Elastic Limit?

Elastic limit is a stage beyond which material cannot bear any further external force maintaining elasticity.

  1. How Would You Define Yield Strength?

It is defined as the maximum force that material could withstand under the condition of yield.

  1. Define Tensile Strength?

It is a maximum strength that the material could withstand before it breaks.

  1. Define Plasticity?

The ability of material that sustains deformation without permanent breaking.

  1. How Would You Define the Hardness of Material?

The resistance offered by the material on its surface against the pressure by other materials

  1. How to Determine the Hardness of a Material?

It includes methods like Brinell hardness, Vicker hardness, and Rockwell hardness.

  1. Define Cast Iron?

An alloy of iron that comprises more than 2.11% of carbon is called cast iron.

  1. In How Many Categories Can Cast Iron Be Divided?

It can be divided into white cast iron, alloy cast iron, ductile cast iron, grey cast iron, and malleable cast iron.

  1. What Are Some Straightforward Methods to Identify Steels?

These methods involve color marking identification, spark identification, and fracture identification.

  1. What Are the Types of The Structure of The Alloy?

The alloy structure can be divided into the mechanical mixture, solid solution, and metal compound.

  1. Define Critical Point?

It is defined as the temperate at which metal starts changing its structure.

  1. Define the Purpose of Carburizing?

Carburizing is done to increase the carbon content on the surface of the steel.

  1. How Would You Define Thermorigidity?

It is referred to as the ability of steel to keep its hardness maintained at different temperatures.

  1. Define Hardenability?

It is referred to as steel’s ability to have a quenching layer at a specified temperature and certain quenching conditions.

  1. Define Thermal Refining?

It is a method that involves tempering at high temperatures and quenching.

  1. Write the Distribution of Aluminum Alloys?

The distribution of Aluminum alloys can be done into cast aluminum alloys and deformed aluminum alloys.

  1. Write the Distribution of Copper Alloys?

The distribution of copper alloys can be done into copper, brass, and bronze.

  1. In Spark Identification, What Are Three Different Types of Sparks?

These three types of sparks are typically tail sparks, foxtail sparks, and pointed tail sparks.

  1. Define Functions of Welding Rod?

It works as a filler metal to the molten pool and conducts the current.

  1. Write Down the Forces on The Molten Drop?

The molten rod forces include surface tension, spot pressure, gravity, electromagnetic compression, arc gas force, and plasma flow force.

  1. What Defects May Occur While Welding Cast Iron?

Stomatal refractory oxide, cracks, white spots, and other defects of this nature

  1. Define Weldability?

It is referred to as a capacity of a metal to get welded. Typically, it means the difficulty of getting healthy welded joints under specified temperature and pressure.

  1. What Are the Possible Causes of Deformation and Stress While Welding?

Uneven and non-equal patterns of cooling and heating cause deformation and stress.

  1. Define the Term ‘Crystallization’?

A process in which a metal is converted into a solid while in a weld pool is called crystallization.

  1. Which Steels Do Possess Common Properties?

These steel types possess the common properties: heat-resistant steel, corrosion-resistant steel, and stainless steel.

  1. How Many Types Are There of Titanium Alloys?

There are three types of titanium alloys: A-type, B-type, and A+B-type.

  1. In How Many Types Can Riveting Be Divided?

Riveting can be divided into three types: docking, angle joint, and lap joints.

  1. Define the Process of Hot Riveting?

The process involves fastening and finishing riveted nail holes, the heating of rivet is done, riveting & piercing is performed. In the end, topstitching & final riveting is done.

  1. How Would You Define Threaded Connection?

It can be defined as a removable fixed connection made up of threaded parts.

  1. Define the Types of Threads That Are Usually Used?

Screw connection, double head bolt connection, and bolt connection

  1. What Types of Washers Are Used to Prevent Loss?

Double ear stop washer, single-ear stops washer, spring washer, and round nut check washer.

  1. Write Down the Important Features Associated with Tangent Plane?

On the same prime line, each of the points has a similar tangent plane.

  1. Define Expandable Surface?

If a surface can be attached clearly with the other surface without creasing and tearing, it will be an expandable surface.

  1. Define Un-expandable Surface?

A solid surface that could not be attached to another solid surface is called an un-expandable surface.

  1. What Is the Most Important Part of Plate Thickness Treatment?

Essential parts of plate thickness treatment are determining the neutral layer of the bending part and the alleviation of plate thickness interference.

  1. Define Blanking and Different Approaches to Accomplish This?

Blanking involves the separation of blanks or parts from the raw material. Approaches used for this are gas cutting and hydraulic cutting.

  1. Write Down the Features of Shear Machining?

Able to cut various steel profiles and metal plates, along with smooth action and high productivity.

  1. What Are the Effects and Types of Post-Shear Angle?

The effect involves the reduction of friction between the cutting blade and material. Meanwhile, the angle ranges from 1.5 to 3 degrees.

  1. How Are Material Properties Affected by The Shear?

It may cause cold hardening and deformation around the edges of the material.

  1. Write Down the Stages of Oxy-Acetylene Cutting Process?

It includes burning off, blowing, and preheating.

  1. What Is the Function of Tempering Safety Device?

It causes the stop of the temper flow that makes sure the safety of acetylene generator.

  1. What Is the Function of Decompression Device?

It stabilizes as well as reduces the pressure.

  1. Write Down the Necessary Preparation for Gas Cutting?

It involves check-cutting oxygen streamline and the preparation of the site.

  1. Define Flame Energy Rate of Preheating?

The flame energy rate for preheating is a unit of consumption of combustible gas per hour.

  1. What Are the Different Types of Preheating Flame?

It involves oxidation flame, carbonization flame, and neutral flame.

  1. Define Drilling?

It is about the drilling of holes on the required surface.

  1. Write Down the Types of Drilling?

There are three types of drilling: center drilling, twist drilling, and flat drilling.

  1. Elaborate the Function of Drill Shank?

It transmits the axial force and torque required to move the drill.

  1. In A Taper Shank Drill, What Is the Role of Flat Tail?

To avoid the drill out in the drill sleeve or central shaft, it increases torque transmission.

  1. Define Cutting Amount?

It is a common term used for cutting depth and cutting speed.

  1. How Would You Define Grinding?

The machining of the surface of the workpiece with the help of a grinding wheel

  1. What Is A Technique to Draw Expansion Diagram?

It involves the radiation method, parallel line method, and triangle method.

  1. According to Structure, In Which Parts Can A Blanking Dye Be Divided?

It can be divided into the guide column die, simple die, and composite die.

  1. Define Blanking Force?

It is a maximum resistance offered by the material to the mold while blanking.

  1. What Should Be the Minimum Bending Radius?

That can get bent without inflicting any deformation on the material.

  1. When Stretching, Why Is Flanging Ring Used?

It is used to avoid wrinkling on the edges of tensile parts.

  1. What Manual Forming Are Included in Sheet Metal Work?

It includes correction, bending, arc bending, flanging, and seam closing.

  1. Define Seam Closing?

The process in which the edges of two plates or two workpieces are folded together.

  1. What Are the Necessary Conditions for Cutting Blanking of Section Steel?

The necessary conditions are I-beam, angle bending of angle steel, and channel.

  1. In How Many Stages Can the Blanking Process Be Divided?

It involves the plastic deformation stage, elastic deformation stage, and shearing stage.

  1. Write Down the Types of Bolt Connection?

Mainly, there are two types of bolt connections, including connection directed to the lateral action and connection performed under the axial tensile load.

  1. For Bolted-Connections, What Are Some of The Anti-Loose Measures?

Anti-loose measures involve mechanical anti-loose and increased friction.

  1. Write Down the Ways to Avoid Mechanical Looseness?

Check-washer, stop-washer, cotter pin, and wire in series can be used to avoid mechanical looseness.

  1. Define Welding Arc?

In a gas medium, a sound and long-lasting discharge occur between the cathode and anode.

  1. How Would You Define the Component of Welding Arc?

It comprises of arc column, cathode area, and anode area.

  1. What Are the Three Directions in Which Electrode Move In?

The directions of movement for the electrode are making a lateral swing, moving in the direction of the molten pool, and moving in the welding direction.

  1. Define Intersection Line?

A component that comprises two or more intersecting geometries

  1. Why Is Rolling Force Calculated?

To make an accurate selection for rolling equipment.

  1. Why Is Blanking Force Calculated?

To design the mold reasonably and choose the capability of equipment.

  1. How Can the Cutting Force Be Reduced?

Cutting force can get reduced by applying step punch, heating of punch die, and inclined blade for cutting.

  1. Why Is Bending Force Calculated?

It is calculated to properly make the design of the mold and choose the bent press.

  1. What Is Included in The Degree of Pull Deformation?

The degree of pull deformation includes maximum allowable deformation of the material’s stretch and mold sticking degree.

  1. What are the materials that are not allowed for cold working correction?

These materials are high alloy steel, cast iron, high carbon steel, and other brittle materials in nature.

  1. What Are the Possible Causes of Deformation in Steel?

Deformation of steel may occur due to internal or external stresses.

  1. How Would You Define Welding Overall Deformation?

The overall change in the shape and size of the structure

  1. How Will You Describe the Hammering Expansion Method?

It is referred to as the elongation of the fiber structure of metal with the help of hammering.

  1. Why Rivet Head Becomes Small After the Process of Riveting?

Because the hole diameter is considerably large while the nail rod is comparatively too short

  1. Define Fusion Welding?

It is referred to as an approach in which welded joint is melted using local heat.

  1. In Assembly, What Types of Clamps Are Used?

Assemble hanger, assembly tools, and mounting fixtures are used.

  1. Jot Down Some of The Commonly Used Assembly Hangers?

The commonly used hangers are chain, wire rope, special hangers, and hand hoists.

  1. What Are Different Types of Guidance for Blanking Die?

Guide plate, guidepost, and guide sleeve are different guides for blanking die.

  1. For Flame Correction, What Could Be the Heating Methods?

Triangle heating and point line heating can be used for this purpose.

  1. What May Be the Different Methods of Drawing?

Transition drawing and direct drawing are mainly used.

  1. What May Be the Different Ways to Determine Length of Curve?

The expansion method and changing of the surface method are used to determine the length of a curve.

  1. What May Be the Different Methods to Find Intersecting Line?

The ridge method and prism methods are used to find intersecting lines.

  1. How Would You Define A Straight Surface?

Typically, it is a surface that is formed up with a straight line.

  1. What May Be the Different Methods to Find 3D Intersecting Line of a Curved Surface?

The latitude line method and tessellation line method are used to find the 3D intersecting line of a curved surface.

  1. What May Be the Different Methods to Find the Actual Length of Line Segment?

These methods include the branch line method, change of surface method, and right triangle method.