Fasteners Flashcards
What is a bolt?
Is a metal rod with external threads on one end and the head on the other.
When a high-quality bolt is threaded into a part without a nut it can also be called?
Cap screw
How do you measure a bolt?
Bolt size, bolt head size, bolt length, and thread pitch
How do u measure a bolts size?
It is a measurement of the outside diameter of the bolt threads
How do you measure a bolt head?
It is the distance across the flats or outer sides of the bolt head. It is the same size as the wrench size.
How do you measure a bolts length?
Is measured from the bottom of the bolt head to the threaded end of the bolt.
How do you measure the thread pitch on a bolt?
Is the same as thread coarseness. With imperial fasteners, it is the number of threads per inch. With metric fasteners, it is the distance between each thread in millimeters.
What are the four thread types?
Coarse threads (UNC unified national coarse) Fine threads (UNF unified national fine) Metric threads (SI system international) Extra fine (UNXF unified national extra fine)
What is the bolt grade or tensile strength?
Refers to the amount of pole or stretch a fastener can withstand before breaking.
What are the two methods used to determine the strength of a bolt?
Slash marks: the more lines the stronger the bolt. Number system (metric bolts): the higher the number the stronger the bolt.
How do you determine the grade of a bolt using the slashmarks or lines on the head?
Always had 2…
For example if the bolt head had three lines on it, simply add 2 to 3. Which means the grade for that bolt is grade 5.
How do you find the grade of a metric bolt?
Metric bolts use a number system, the number shown on the top of the bolt is not only the strength but also the grade it is.
Example: bolt head reads 8, that means the grade of the bolt is grade 8.
What does SAE stand for?
Imperial
What are imperial fasteners measured in?
Measured in inches
What are metric fasteners measured in?
Measured in millimetres
What can you use that is found in a shop to measure the threads of a bolt?
You can use a tap from the tap and die set. Just find the tap that fits, and the number on top of the tap is the measurement of the threads of the bolt.
You can also use a ruler
What is the terminology for a nut?
Has internal threads and usually is a hex (6sided) outer shape. When a nut is screwed onto a bolt, a powerful clamping force is produced.
What tools can be used to restore external threads?
Thread file, rethreading tool, rethreading die
What tools can be used to restore internal threads?
Internal thread chaser, hand tap
What is a helicoil?
A HeliCoil is a coiled-wire type of thread repair insert used to create internal screw threads to accommodate standard-sized fasteners.
What devices are used for locking nuts and bolts?
Cotter pin, lock wire, flat metal locks, lock ears
What methods can be used to remove a seized nut?
Penetrating oil, nut splitter, hacksaw, chisel, has torch for heat
What is the difference between a flat washer and a lock washer?
Flat washers increase the clamping surface under the fastener, and prevent the fastener from digging into the part.
Lock washer prevent the bolt or but from becoming loose under stress and vibration.
What are torque specifications?
Are tightening values for bolts and nuts that is given by the auto manufacturer.
What happens if a bolt or nut is under tightened?
A bolt could work loose and fall out. Part movement could also shear the fastener or break a gasket causing leakage.
What is bolt sequencing?
It is a bolt tightening sequence or pattern that is used to assure parts are fastened evenly.
What happens when there is an incorrect sequence or uneven tightening of a fastener?
Can cause breakage, warpage, gasket leaks, and other problems.
What is a gasket?
A gasket is a soft, flexible material which is placed between parts to prevent leakage.
What are gaskets made out of?
Fibre materials, rubber, neoprene (synthetic rubber), Cork, treated paper, or thin steel.
What happens to the gasket when you tighten fasteners together?
The gasket Is compressed and deformed. This forces the gasket material to fill small gaps, scratches, dance, or other imperfections in the part services. This way I’ll leakproof seal is produced.
What is a hardening sealer used for?
Are for permanent assemblies such as fittings and threads, and for filling on even surfaces. They are usually resistant to heat and most chemicals.
What is a nonhardening sealer used for?
Are for semi permanent assembly’s such as cover plates, flanges, threads, hose connections and numerous other applications. They are also resistant to most chemicals and moderate heat.
Explain when RTV and anaerobic sealers are recommended.
RTV recommended for use with thin flexible flanges, it uses moisture from the air to dry.
Anaerobic recommended use for tightly fitting thick parts.
What are five rules for working with seals?
Type, temperature range, their use, what they are resistant to, and there characteristics.
What is a self threading screw?
A screw that threads its own hole when being screwed into something.
Define seals
Seals prevent leakage between a stationary part and a moving part.
What are adhesives used for?
Adhesives are widely used on most late model cars. They hold body mouldings, rubber weatherstripping, and body emblems in place.
What are self threading metal screws used for?
Sheet metal
What is the difference between a stud and a threaded rod?
A stud has a space In the middle
What is the advantage of a stud instead of a thread rod?
A stud can have a different thread pitch in each end
Can RTV be used instead of a gasket?
Yes
What are the Sealer components?
Spring, inner lip, body/housing
Can O-rings be used on a waterpump instead of a gasket?
Yes
What is the shape of a carrot bolt head?
Round
Do rivers have threads?
No
When would you use a wing nut?
Low torque, and easy access
When in the shop you are sent to grab a lock washer, what lock washer are you grabbing?
A split spring lock washer
What are 3 common washers that are used?
Toothed lock washer, flat washer, split spring washer
What are snap rings used to retain?
Shaft on transmissions, wheel barring, door handles
Nicks and Bers in housing and shafts do not affect the seals ability to work properly? True or false
False
Do snap rings have internal threads
No
What shape is a woodruff key?
A half moon
How is a unified national thread pitch measured?
Threads per inch
What tool can be used to measure thread pitch?
Thread pitch gauge
What other means besides the thread pitch gauge may be used to measure thread pitch?
Imperial ruler
Speed nuts are used when space is tight and light torque is required? True or false
True
A jam nut or a pal nut is used to lock a bolt or a threaded rod? True or false
False
What do we use to install and remove snap rings?
Span ring pliers
Which way does a left hand thread turn?
Counterclock wise
Do we use heat to loosen threads on c steering components?
No
