Types Of Bolts And Nuts

  • Author: Farhan Khan
  • Posted On: July 3, 2020
  • Updated On: July 3, 2020

Types Of Bolts And Nuts

A nut is a type of fastener with a threaded hole. Nuts are almost always used in conjunction with a mating bolt to fasten multiple parts together. The two partners are kept together by a combination of their threads’ friction (with slight elastic deformation), a slight stretching of the bolt, and compression of the parts to be held together. Bolt and nut may sound similar but they have a huge difference which we have descried below

Classification Of Nuts

Classification Of Nuts

HEX NUT – The most common hexagonal fastener with internal threads that screws on to the shank of a bolt or a hex cap screw.



MACHINE SCREW NUT – Machine screw nuts are designed to mate machine with screws, screws commonly used in metal fastening.


Nylon Insert Lock – A nut with a nylon insertto prevent backing off.
Also referred to as a Nylock



JAM – a hex nut with reduced height



Nylon Insert Jam Lock – A nylock nut with a reduced height




Wing – A nut with ‘wings’ for hand tightening.


Cap – A nut with a domed top over the end of the fastener.


SQUARE – A four sided nut.

A bolt is a form of threaded fastener with an external male thread. Bolts are thus closely related to, and often confused with, screws.

Classification Of Bolts

Flange Bolt

FLANGE BOLTS Flange bolts have a flange on the bottom of the head that distributes the load like a washer.


Socket Head

SOCKET SCREWS – Socket screws, also known as Allen head are fastened with a hex Allen wrench

Shoulder Eye Bolt

EYE BOLTS – A bolt with a circular ring on the head end. Used for attaching rope or chain.

Hex bolt

HEX BOLTS – Bolts with a hexagonal head with threads for use with a nut or tapped hole.

Carriage bolt

CARRIAGE BOLTS – Bolts with a smooth rounded head that has a small square section underneath.

Lag bolt

LAG BOLTS – Bolts with a wood threadand pointed tip. Abbreviated Lag.

Hanger Bolt

SHOULDER BOLTS – Shoulder bolts (also known as stripper bolts) are used to create a pivot point.

Hanger Bolt

ELEVATOR BOLTS – Elevator bolts are often used in conveyor systems. They have a large, flat head.

Hanger Bolt

HANGER BOLTS – Hanger bolts have wood thread on one end and machine thread on the other end.



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Author: Farhan Khan

Farhan is a highly experienced civil engineer from the Southern side of Texas and has been associated with ConstructionHow since 2020. Over almost a decade, his wide span of expertise enabled him to bring forth his fair share of stories and experiences related to the most iconic engineering examples worldwide. He has also contributed to online and offline publications on requests. Engineering is his passion, which is why he chose to become part of our honorable team of industry experts looking to provide authentic and credible guidelines to the reader.