WPM-Carpentry, Assignment-1 PDF

# MECHANICAL ENGINEERING DEPARTMENT ## PRACTICAL: 3 Carpentry ### SEMESTER -1/1I (WORKSHOP) ### 3.1 Introduction: Carpenters are skilled craftsmen who build structures and products from wood and other similar materials. Carpentry and joinery are common terms used with any class of work with wood...

# MECHANICAL ENGINEERING DEPARTMENT ## PRACTICAL: 3 Carpentry ### SEMESTER -1/1I (WORKSHOP) ### 3.1 Introduction: Carpenters are skilled craftsmen who build structures and products from wood and other similar materials. Carpentry and joinery are common terms used with any class of work with wood and other similar materials. Carpentry deals with all constructional work of building such as making of doors, windows, cupboards, stairs etc. It is also used to make the prototypes of the product using wood materials. ### 3.2 Carpentry Material/s: There are many varieties of stock available to woodworkers. Each species has different rules for getting the most out of that particular type of wood. In this list, find woodworking tips for dealing with just a few of the most popular varieties of wood used for woodworking, such as oak, maple, pine and more. | Name | Colour | Density | Characteristics, Usage and Status | |------------|------------------|-----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | Babul | Whitish red | 835 kg/m³ | It is strong, hard and tough and it takes up a good polish. It is used for such products as bodies and wheels of bullock cart, agricultural instruments, tool handles, and well curbs. | | Deodar | Yellowish brown | 560 kg/m³ | Deodar is the most important timber tree providing soft wood. It can be easily worked and it is moderately strong. It possesses distinct annual rings. It is used for making cheap furniture, railway carriages, railway sleepers, packing boxes, structural work and so forth. | | Mahogany | Reddish brown | 720 kg/m³ | It takes a good polish and is easily worked. It is durable under water. It is most commonly used for furniture, pattern making and cabinet work. | | Mango | Deep gray | 560-720 kg/m³ | The mango tree is well known for its fruits. It is easy to work and it maintains its shape well. It is moderately strong. It is most often used for cheap furniture, toys, packing boxes, cabinet work, and panels for doors and for windows. | | Oak | Yellowish brown | 865 kg/m³ | Oak is strong and durable, with straight silvery grain. It is used for preparing sporting goods. | | Sal | Brown | 880-1050 kg/m³ | It is hard, fibrous and close-grained. It does not take up a good polish. It requires slow and careful seasoning. It is durable under ground and water. It is used for railway sleepers, shipbuilding, and bridges. | | Sandalwood | White or Red | 930 kg/m³ | It has a pleasant smell. It is commonly used for agricultural instruments, well curbs, wheels, and mallets. | | Sissoo | Dark brown | 770 kg/m³ | Also known as shisham or tali, this wood is strong and tough. It is durable and handsome and it maintains its shape well. It can be easily seasoned. It is difficult to work but it takes a fine polish. It is used for high quality furniture, plywoods, bridge piles, sport goods, railway sleepers and so forth. It is a very good material for decorative works and carvings. | | Teak | Deep yellow to dark brown | 639 kg/m³ | Moderately hard, teak is durable and fire-resistant. It can be easily seasoned and worked. It takes up a good polish and is not attacked by white ants and dry rot. It does not corrode iron fastenings and it shrinks little. It is among the most valuable timber trees of the world and its use is limited to superior work only. | | Mulberry | Brown | 650 kg/m³ | It is strong, tough and elastic. It takes up a clean finish. It can be well seasoned. It is turned and carved easily. Mulberry is typically used for baskets and sports goods like hockey sticks, tennis rackets and cricket bats. | ### Engineered Wood Engineered wood, also called composite wood or **man-made wood**, includes a range of derivative wood products which are manufactured by binding together the strands, particles, fibers, or veneers of wood, together with adhesives, to form composite materials. These products are engineered to precise design specifications which are tested to meet national or international standards. - Engineered wood products are used in a variety of ways, often in applications similar to solid wood products. Engineered wood products may be preferred over solid wood in some applications due to certain comparative advantages: - Because engineered wood is human-made, it can be designed to meet application-specific performance requirements. - Large panels of engineered wood may be manufactured from fibers of small diameter trees. - Small pieces of wood, and wood that has defects, can be used in many engineered wood products, especially particle and fiber­based boards. **Following are the some of the manmade woods generally used for industrial and household applications:** - **1. Plywood** - Plywood is a manufactured wood, made by gluing together a number of thin veneers or plies of softwood or hardwood. It is used mostly in commercial sites, purely because it is a strong durable substance. - **2. Block board:** - Block board is made up of a core of softwood strips. These strips may be up to about 25mm wide. The strips are placed edge to edge and sandwiched between veneers of hardwood. The sandwich is then glued under high pressure. - Blockboard is not suitable for outdoor use because the glues used are interior glues. When using blockboard to make such things as doors or tables, it is important to ensure that the core runs lengthways in order to achieve maximum strength. Blockboard may be used to make shelves, doors, paneling and partitions. Block board is sold in sheets of 2440 x 1220mm and are normally 30mm thick. - Screws and nails may be used to attach block board and laminboard but you have to ensure that you make contact with the strips of softwood and not the gaps between the softwood strips. The edges of both block board and lamin board are unattractive and cannot be cleaned up well. Place softwood strips, veneers or fill and paint the edges. Block board and lamin board may be bought with a variety of applied finishes such as wood veneers and plastic laminate surfaces. If both sides are treated in the same way block board and lamin board have a good resistance to warping. ### 3.3 Tools and Equipments used in Carpentry Shop: The tools that are used for carpentry work are as follows: 1. Marking and measuring tools 2. Cutting tools 3. Planning tools 4. Boring tools 5. Sinking tools 6. Holding tools ## 3.4 Marking and Measuring Tool ### 3.4.1 Carpenter's Rule Measuring stick consisting of a strip of wood or metal or plastic with a straight edge is used for drawing straight lines and measuring lengths. It are made portable by folding (carpenter's folding rule) or retracting into a coil (metal tape measure) when not in use. When extended for use they are straight. They are in the range of 0-60 cm. ### 3.4.2 Straight Rule A straight rule, or rule, is an instrument used in geometry, technical drawing and engineering/building to measure distances and/or to rule straight lines. The ruler is essentially a straightedge used to rule lines and the calibrated instrument used for determining measurement. ### 3.4.3 Try Square A try-square is a woodworking or a metal working tool used for marking and measuring a piece of wood. The square refers to the tool's primary use of measuring the accuracy of a right angle (90 degrees); to try a surface is to check its straightness or correspondence to an adjoining surface. A piece of wood that is rectangular, flat, and has all edges (faces, sides, and ends) 90 degrees is called four square. A board is often milled four squares in preparation for using it in building furniture. it is useful for getting right angles Try-square is sometimes spelled "tri square". ### 3.4.4 Marking Gauge A marking gauge is used to mark a line parallel to a straight edge. The stem and stock are made from beech and the thumbscrew from clear yellow plastic. The better quality gauges have brass inserts at the front of the stock. These help reduce the wear on the stock as it is pushed against the surface of the wood - to be marked. The marking gauge is an extremely important tool for marking parallel lines and preparing for cutting joints. ### 3.4.5 Divider A divider, also known as a measuring compass, is a mathematical, drafting or cartographic instrument used to aid measurements of the length of irregular lines and of distances on maps or charts. It is commonly used in geometry and in nautical navigation. It is similar in appearance to a drafting compass, the difference being that the drafting compass has a spike on one end and a pencil (or other drawing utensil) on the other which allows the drawing of circles, whereas the dividers has spikes on both ends. Often a compass can be fitted with a spike in place of the drawing utensil and thus converted to dividers. ## 3.5 Cutting Tools ### 3.5.1 Saws A saw is a tool that uses a hard blade with an abrasive edge to cut through softer materials. The cutting edge of a saw is either a serrated blade or an abrasive. A saw may be worked by hand, or powered by steam, water, electricity or other power. ### 3.5.2 Rip Saw In woodworking, a cut made parallel to the direction of the grain of the workpiece is known as a rip cut. If one were to cut a tree trunk in half from top to bottom, this would be a rip cut but the term also applies to cutting free lumber. A rip saw is a saw that is specially designed for making rip cuts. The cutting edge of each tooth has a flat front edge and it is not angled forward or backward. It is about 700 mm long with 3-5 points or teeth per 25 mm. ### 3.5.3 Cross Cut Saw A crosscut saw is a saw that is specially designed for making crosscuts. A crosscut is a cut made horizontally through the trunk of a standing tree, but the term also applies to cutting free lumber. Crosscut saws have teeth that are designed to cut wood at a right angle to the direction of the wood grain. The cutting edge of each tooth is angled back and has a beveled edge. This design allows each tooth to act like a knife edge and slice through the wood, in contrast to a rip saw, which tears along the grain, acting like a miniature chisel. It is about 650 mm long with 8 – 10 points or teeth per 25 mm. ### 3.5.4 Panel Saw Panel saw is any type of sawing machine that cuts sheets into sized parts. Panel saws are used by cabinet shops to easily cut plywood and melamine sheets into cabinet components. They are also used by sign shops to cut sheets of aluminum, plastic and wood for their sign blanks. Panel saws typically fall into one of two categories: Horizontal and Vertical. Some higher end panel saws feature computer controls that move the blade and fence systems to preset values. Other lower end machines offer simplicity and ease of use. It is about 500 mm long with 10 – 12 points or teeth per 25 mm. ### 3.5.5 Tenon or Back Saw A backsaw is any hand saw which has a stiffening rib on the edge opposite the cutting edge, allowing for better control and more precise cutting than with other types of saws. Backsaws are normally used in woodworking for precise work, such as cutting dovetails, tenons in cabinetry and joinery. Because of the stiffening rib, the backsaws are limited in the depth to which they can cut. Backsaws usually have relatively closely-spaced teeth, often with little or no set. It is about 400 mm long with 12 - 13 points or teeth per 25 mm. ### 3.5.6 Dovetail Saw A small backsaw used by furniture makers to cut dovetails and other fine joints. Besides its small size, the distinguishing feature of the dovetail saw that separates it from other backsaws is the thickness of its blade - about 26 gauge. Other backsaws can be about 0.65 mm – 1 mm depending on length and intended purpose. A thin blade and its resulting kerfs allow the most accurate saw cut for a small joint like a drawer's dovetail. It is about 200 mm long with 12-13 points or teeth per 25 mm. ### 3.5.7 Bow Saw A bow saw is a metal-framed saw in the shape of a bow with a coarse wide blade. This type of saw is also known as a sewed saw or a buck saw. It is a rough tool that can be used for cross-cutting branches (maybe up to 6 inches in diameter) down to size. Traditionally, a bow saw is a woodworking tool used for straight or curved cuts. ### 3.5.8 Compass Saw A handsaw with a narrow triangular blade is used for cutting circles and curves in wood. Compass saws have longer, coarser blades than keyhole saws. They are designed for slightly heavier work such as cutting holes in subflooring for plumbing or electrical wiring. ### 3.5.9 Chisels A chisel is a tool with a characteristically shaped cutting edge (such that wood chisels have lent part of their name to a particular grind) of blade on its end, for carving or cutting a hard material such as wood, stone, or metal. The handle and blade of some types of chisel are made of metal or wood with a sharp edge in it. In use, the chisel is forced into the material to cut the material. The driving force may be manually applied or applied using a mallet or hammer. In industrial use, a hydraulic ram or falling weight ('trip hammer') drives the chisel into the material to be cut. ### 3.5.10 Firmer Chisel The firmer chisel is used to remove fairly large pieces of waste and because the blade is thicker it can withstand rough treatment, but not hitting with a mallet. The paring chisel is used for taking off small quantities of wood in thin slices. The blade is thinner and will not stand knocking about. The mortise chisel is used for chopping mortises (rectangular holes) and is robust with a shock absorbing washer to enable it to be struck with a mallet. It has blade about 125 mm long and the width varies from 1.5 to 50 mm. ### 3.5.11 Bevel Chisel A chisel is used for cutting wood, having its cutting edge at an angle to the sides. They are slightly undercut making them easy to push into corners. They are normally used for finishing dovetail joints. ### 3.5.12 Mortise Chisel Mortise chisels are used for 'chopping out' joints (chiseling away the waste wood). They are particularly useful for cutting mortise joints as they are strong enough to withstand heavy blows with a mallet. Blade width varies from 3-16 mm. ## 3.6 Planning Tools ### 3.6.1 Jack Plane A jack plane is the general-purpose bench plane, used for general smoothing of the edges, sizing of wood and jointing edges. Jack planes are about 400 mm long and the blade can have either a slightly curved edge for smoothing stock, or a straight edge for jointing stock. ### 3.6.2 Trying Plane Trying plane is a type of hand plane used primarily to straighten the edges of boards in the operation known as jointing. A jointer plane may also be used to flatten the face of a board. Its long length is designed to 'ride over' the undulations of an uneven surface, skimming off the peaks, gradually creating a flat surface. In thicknessing or preparing rough stock, the jointer plane is usually preceded by the jack plane and followed by the smoothing plane. These are typically 510 to 610 mm long. ### 3.6.3 Smoothing Plane A smoothing plane or smooth plane is a type of bench plane used in woodworking. The smoothing plane is typically the last plane used on a wood surface - when used properly; the finish it gives will be far superior to that made by sandpaper or scrapers. The smooth finish is the result of planning the wood off in strips, rather than by successive buffing and scratching. The smoothing plane is typically 8 to 10 inches long. ### 3.6.4 Rebate Plane The rebate plane (also known as the rabbet plane) is a hand plane designed for cutting rebates in wood. The rebate plane is one of a group of planes including the shoulder plane, bull nose plane and carriage makers plane in which the blade protrudes by a very small amount - usually less than half a millimeter - from the sides of the plane body on both sides. The blade is very slightly wider than the body of the plane. The reason for the slight protrusion of the blade is so that the plane body does not bind on the side of the cut, which would result in the side wall of the rebate not being perpendicular to the bottom. Rebate planes are intended for long grain cutting and are generally setup to remove large amounts of material quickly. ### 3.6.5 Metal Plane The metal plane serves the same purpose but facilitate a smoother operation. The body of the metal plane is made of a grey iron casting. The thickness of the shaving blade removed is governed by a fine screw adjustment and a lever is used for adjusting the blade at right angle. ## 3.7 Boring Tools Boring tools are used to make round holes in wood and they are selected according to the type and the purpose of the hole. They include bradawl, gimlet, brace and drill bit. ### 3.7.1 Bradawl A bradawl is a tool with a blade similar to that of a straight screwdriver and a handle made from wood or plastic. A bradawl is used to make an indentation in wood or other materials in order to ease the insertion of a nail or screw. The blade is placed across the fibers of the wood, cutting them when pressure is applied - the bradawl is then twisted through 90 degrees which displaces the fibers creating a hole. This cutting action helps to prevent splitting of the wood along the grain. ### 3.7.2 Gimlet A gimlet is a hand tool for drilling small holes, mainly in wood, without splitting. A gimlet is always a small tool. The cutting action of the gimlet is slightly different; the cutting edges pare away the wood which is moved out by the spiral sides, falling out through the entry hole. This also pulls the gimlet further into the hole as it is turned; unlike a bradawl, pressure is not required once the tip has been drawn in. ### 3.7.3 Drill Bit Drill bits are cutting tools used to create cylindrical holes. Bits are held in a tool called a drill, which rotates them and provides torque and axial force to create the hole. Specialized bits are also available for non-cylindrical-shaped holes. ## 3.8 Striking Tools ### 3.8.1 Hammers A hammer is a tool meant to deliver an impact to an object. The most common uses are for driving nails, fitting parts, forging metal and breaking up objects. Hammers are often designed for a specific purpose, and vary widely in their shape and structure. The usual features are a handle and a head, with most of the weight in the head. The basic design is hand-operated, but there are also many mechanically operated models for heavier uses. ### 3.8.2 Mallets A mallet is a kind of hammer, usually of wood, smaller than a maul or beetle and usually with a relatively large head. Wooden mallet, usually used in carpentry to knock wooden pieces together or to drive dowels or chisels. A wooden mallet will not deform the striking end of a metal tool, as most metal hammers would, but it also reduces the force available to drive the cutting edge of a chisel. Hardwood mallet is also used to knock in a cricket bat. Rubber mallets are used when a softer blow is called for than that delivered by a metal hammer. They are typically used to form sheet metal, since they don't leave marks, as well as for forcing tight-fitting parts together, for shifting plasterboard into place, in upholstery, and a variety of other general purposes, including some toys. It is the most commonly used mallet. ## 3.9 Holding Tool ### 3.9.1 Bench Vice A vise or vice (see American and British English spelling differences) is a mechanical screw apparatus used for holding or clamping a work piece to allow work to be performed on it with tools such as saws, planes, drills, mills, screwdrivers, sandpaper, etc. Vises usually have one fixed jaw and another, parallel, jaw which is moved towards or away from the fixed jaw by the screw. ### 3.9.2 Bench Stop Bench stop is simply a block of wood projecting above the top surface of the bench. This is used to prevent the wood from moving forward when being planned. The other types of holding devices used are bench holdfast, sash clamp, G cramp, hand screw etc. ## 3.10 Carpentry Joints There are many kinds of joints used to connect wood stock. Each joint has a definite use and requires lay in-out, cutting them together. The strength of the joint depends upon amount of contact area. If a particular joint does not have much contact area, then it must be reinforced with nails, screws or dowels. ### 3.10.1 Lap Joint In lap joints, an equal amount of wood is removed from each piece, as shown in figure. Lap joints are easy to layout, using a try­-square and a marking gauge. Follow the procedure suggested form sawing and removing the waste stock. If the joint is found to be too tight, it is better to reduce the width of the mating piece, instead of trimming the shoulder of the joint. This type of joint is used for small boxes to large pieces of furniture. ### 3.10.2 Mortise and Tenon Joints It is used in the construction of quality furniture. It results in a strong joint and requires considerable skill to make it. The following are the stages involved in the work. - Mark the mortise and tenon layouts. - Cut the mortise first by drilling series of holes within the layout line, chiseling out the waste stock and trimming the corners and sides. - Prepare the tenon by cutting and chiseling. - Check the tenon size against the mortise that has been prepared and adjust it if necessary. ### 3.10.3 Bridle Joint This is the reverse of mortise and tenon joint in form. The marking-out of the joint is the same as for mortise and tenon joint. This joint is used where the members are of square or near square section and unsuitable for mortise and tenon joint. ## Assignment 3.1 1. What does mean by carpentry? 2. What is the difference between timber and wood? 3. Name the various Indian timbers? Explain any eight types of the Indian timber. 4. What are the different types of the manmade wood? Explain any one in detail. 5. Classify the tools used in carpentry shop. 6. List the various marking and measuring tools. 7. Explain the following with neat sketch: - a. Carpenter's Rule - b. Try Square - c. Marking Gauge 8. List the various cutting tools. 9. Explain the following with neat sketch - a. Cross Cut Saw - b. Tenon Saw - c. Dovetail Saw - d. Bow Saw - e. Firmer Chisel - f. Bevel Chisel - g. Mortise Chisel 10. List the various planning tools in carpentry. 11. Explain the following with neat sketch - a. Jack plan - b. Metal Plane - c. Rebate Plane 12. What does mean by boring tools? List the various boring tools. 13. Explain the following with neat sketch - a. Bradawl - b. Gimlet 14. Explain the following with neat sketch - a. Bench Vice - b. Hammer - c. Mallet 15. Explain the following carpentry joints stating their applications: - a. Lap Joint - b. Mortise & Tenon Joint - c. Bridal Joint ## Assignment 3.2 Prepare the carpentry job in the Mechanical Workshop as per given drawing. *** The document contains a table and a diagram. The table lists different types of wood and describes their characteristics, usage, and status. The diagram shows various carpentry tools and joints.