Wednesday, July 3, 2013

Workshop Maintenance Tools..Definite Read Part-3

WorkShop Tools Part-3

Maintainence Tools
(content courtesy:

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Dismantling And Assembling

Safety Reminders
•        Always wear safety glasses, safety boots, hair protection and suitable clothing while in the workshop
•        Lift the right way
•        Do not use a machine fitted with a Danger Tag
•        Know where the First Aid station is
•        No running or horseplay
•        Use ear muffs of plugs for protection against noise.

Special Rules For This Section
•        Make sure you select the right type and size of spanner for each job
•        Make sure the machine is held securely
•        Check the drawing before removing any components to avoid being injured by a flying spring etc.





Mechanical Tools


When adjusting nuts and bolts, the correct size and type should always be used. This greatly reduces the risk of damage to the nut or bolt and the spanner. The risk
of personal injury due to a spanner slipping is also minimised
by pulling towards the user.The size is determined by the nut
or bolt it fits. The distance across the flats of a nut or bolt
varies both with the size and the thread system. There are three
thread systems to consider:

Text Box:  Metric Standard system
Spanners for metric bolts are marked with the size across the jaw opening, followed by the abbreviation "mm,.e.g. 15 mm.

British system
The nominal size of the bolt is used to identify the spanner.

A spanner to fit a British Standard bolt with a half‑inch nominal diameter would be marked 1/2 BS.

A spanner to fit a heavy series British Standard Whitworth bolt with a seven‑sixteenths of an inch nominal diameter
would be marked 7/16 W.

As the heavy W series will fit one size above a BS series the 7/16 W spanner will also a fit a 1/2 BS bolt.

British Association spanners are made with the size numbers followed by the letters BA.

Unified Standard system
Spanners for Unified bolts are marked:

with a number based on the decimal equivalent of the nominal, factional size across the flats of the hexagon before the sign
AF, e.g. 50 AF; or

with the fractional size across the flats before the sign AF,
e.g. 1/2 AF. As American nuts and bolts now conform to the
 Unified Standard, the SAE series spanners are interchangeable
 with the Unified series.

Open ended spanners have their neads offset at 15º to enable full rotation of a square nut when the shank can move no more than 45ºof arc. Such a spanner will give full rotation of a hexagonal nut when the shank is limited to 30º of arc.
Hexagonal nuts ring spanners (six sided) require 60º before they can be re-engaged.
Double hexagonal ring spanners (twelve sided) require 30º before they can be re-engaged.

Single End Spanner
Single end spanners come in a wide range of sizes from very small (5 mm) to very large (75 mm) or more. They are normally of a heavier construction than other spanners in the larger sizes so that nuts and bolts may be tightened or loosened by hitting the spanner with a hammer.

Single-end spanner

Podge Spanner
The podge spanner is used on bridge and construction work where holes drilled in steel girders have to be aligned so that rivets or bolts may be put through the holes. The tapered point is used to enter the two holes and lever them into alignment.

Podge spanner

Open Ended Spanners
Open ended spanners are available in ranges of imperial and metric sizes. They generally have different sizes on each end. Open ended spanners are usually the easiest to slip over a hexagon but can slip off.

Ring Spanners
Ring spanners are the least likely to slip and/or damage the hexagon they are trying to undo. They also have different sizes on each end. Ring spanners are offset to allow clearance for the operators knuckles. Because of the offset there is a slight tendency for the spanner to roll off the top of the nut when force is applied.

Combination Open End And Ring Spanners
Combination spanners have the same size at both ends. They give the advantages of both the open end and ring spanners in a single tool. Because the spanner is straight with no offset, force is applied directly in line with the nut or bolt head and there is no tendency for a correctly fitting spanner to roll off the top of the nut or bolt head.

Tube Or Box Spanners
Tube or box spanners are made from tubular steel formed at both ends into a hexagon. Because of their thin wall design, they can be used in places where there is little clearance between the nut or bolt head and the clearance hole in which it is located. A spanner can be used on one end to apply force or a bar can be used through the hole in the body of the spanner to apply the force to tighten or loosen the nut.

Socket Spanners
Socket spanners are the fastest way of undoing or doing up a bolt or nut. They are used with a variety of accessories. They are available as 6 point (single hexagon) or 12 point (double hexagon). The 12 point socket enables faster positioning of the socket. Some sockets are available in extended length bodies specifically designed to remove spark plugs from motor engines.

Socket Accessories

Torque Wrench
Torque wrenches are used with sockets to tighten screwed parts to a specified tension.

Adjustable Spanner
The adjustable wrench, commonly called a “shifter” should only be used when a correct sized spanner is not available. Although it is convenient because it can be adjusted, the shifter is more likely to slip and cause damage to both the nut and the operator.

Special Purpose Spanners
There is a variety of special purpose spanners that are readily available. Some of those spanners are shown below.

Half moon spanner                                                                      Crows foot spanner                                                                                                  


“C” spanner                                                                     Tube nut spanner    


Hook spanner

                                                                                                                               Screw Drivers

Flat screw drivers tips should be a little smaller than the length of the bottom of the screw slot. Slightly hollow‑grinding them allows the tip to clear the top edge of the slot while reducing the amount of downward pressure required when turning the blade. It also brings the faces of the tip almost parallel to the sides of the slot
Screw drivers are available with a straight head, a Phillips head or  Posi-drive head. The latter two are unlikely to slip from clean matching recesses but require more downward pressure than flat tip screwdrivers.

Some screwdrivers have insulated blades and handles for use in electrical work.

                 Straight screwdrivers                                                 Phillips screwdriver

Special Drivers
Off set screw drivers are used when space around the screw prevents a standard Phillips or flat stubby screw driver from being used.

Impact Drivers
Impact drivers are used to tighten or loosen screws or nuts by using a hammer blow to the end of the impact driver. The hammer blow keeps the driver bit firmly on the head of the screw whilst a helical slide inside the body turns the driver. Most impact drivers can accept sockets as well as a full range of driver bits.

Impact screwdriver

Hexagon Wrenches
Hexagon wrenches, also known as “Allen” keys, are used to drive screws with a recessed hexagon. The keys are available as an “L” shape “Tee” wrench or as hexagon screwdrivers and usually are supplied in a fold up set in sizes from 1.5 mm to 10 mm. The full range of sizes is from 0.71 mm to 27 mm.


There is a wide variety of pliers available. The most commonly used type is combination pliers. They are used to hold flat and round material and to cut small diameter material such as copper wire and shearing split cotter pins.

Other types include:
•        long nose - straight and bent

•           slip joint or multi-grips

•        circlip - internal and external

•        locking pliers or vice grips

Pipe Wrenches
Designed to grip pipes or cylindrical couplings, pipe wrenches are available as Stillson pattern, foot print and chain types.

Riveting Tools

Used to install pop rivets, there is a variety of light and heavy duty riveting tools.

Care Of Hand Tools

•        use the right tool for the job
•        use the tools in a safe way
•        store the tools to prevent damage
•        return tools to their right place
•        repair or mark faulty tools.
•        use the tool for the purpose it was designed for; i.e. never use files or screwdrivers as levers
•        lubricate tools as necessary and always store tools lightly oiled or wrapped in oiled paper to prevent corrosion


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