Care and maintenance of metal work tools

Care of Files

(i) A file cuts the metal during the forward stroke; therefore pressure on the file should be released during the return stroke.

(ii) A new file should be used for soft metals such as brass, zinc, or copper. It should not be used for filing welded joints or surface of casting.

(iii) A file must not be used without a handle because it is dangerous. Make sure the handle is firmly secured.

(iv) The file should be cleaned regularly with a wire brush or file card to remove iron filing embedded in the teeth of the file and enable the file to cut better.

Care of Hacksaw

(i) Ensure the jobs are rigidly clamped to the vice.

(ii) The blade should be fixed so that the teeth are pointing away from the handle.

(iii) Tension the blade by the tensioning wing-nut making sure that the tension is right. Incorrect tension will lead to breakage of the blade.

(iv) For solid copper or brass, use coarse blade about 14 to 18 teeth per 25mm for sheet metal and thin strip use teeth per 25mm.

(v) Use moderate speed in cutting, about 40 to 60 strokes per minute.

(vi) Use as much length of the blade as possible.

Care of Boring Tools

(i) With a bradawl, mark the position of the screw hole

(ii) Select the proper size of drill bit

(iii) Countersink the shank hole for countersunk head or flat head screw by using correct countersink

(iv) Fasten the two woods A and B in the wood vice

(v) Select suitable screw driver squarely in the screw slot.

Concept of and Need for Maintenance

The Concept of Maintenance

Maintenance is defined as the work done on any engineering equipment to keep it in good operating condition. Everything we have in our school and home need to be taken care of so that they can serve us better. A driver checks the oil level, radiator water, battery, tyres, brakes etc in his car to see if there is any problem before he hits the road.

The Need for Maintenance

The following are the reasons or need for the maintenance of any item:

1. To make the equipment function properly
2. To avoid preventable breakdown
3. To reduce chances of accidents and ensure safe use
4. To avoid the inconvenience of equipment failure
5. To make the item last longer ;and
6. To reduce loss of time and thereby save money.

Types of Maintenance

The types of maintenance carried out on machines and equipment are grouped under the following:

1. Predictive maintenance
2. Preventive maintenance
3. Corrective maintenance

Predictive Maintenance

This is the maintenance carried out using computers and other devices to predict impending breakdowns. Once the predictions are made, necessary remedies are immediately designed and applied to avoid those breakdowns.

Basically, predictive maintenance reduces the amount of other types of maintenance to be carried out on the equipment. However, what is important here is to carry out a routine check on the facilities for the predictive maintenance to ensure that they are still in place and functioning.

Preventive Maintenance

This is the type of maintenance carried out on equipment before breakdown occurs. Typical examples of preventive maintenance are:

(i) Regular servicing of cars

(ii) Regular oiling or lubricating of moving parts

(iii) Regular painting of corrosive metal

(iv) Regular cleaning of equipment routine checks on lubricants, safety gurds, nuts and bolts, studs, signal indicators.

(v) Routine checks on level of wears, alignment, tension of belt and chains.

Corrective Maintenance

This involves actions taken to correct or restore broken down equipment to a functional state. The equipment may need a total overhaul and some parts may need to be replaced or repaired, and both require money and time.

EVALUATION

1. What is maintenance?
2. How can we maintain our items?
3. Mention the types of maintenance
4. State which of the three types of maintenance we should avoid. Give one reason for your answer.
5. Why do we need to maintain our equipment?