29th April 2020, Period 2, Class 12, Engineering Graphics, Machine Parts - Hexagonal Bolt - 2

Dear Students,

Good Morning and a warm welcome to today's class.

It feels really nice to meet up for yet another class this morning.

Recall that in our last class, we had learnt about square nut and its projections. 

Let us now proceed further and learn about Hexagonal Headed Bolt and its orthographic views.


HEXAGONAL HEADED BOLT

It is the most commonly used bolt. The head of the bolt is in the shape of a hexagon prism (or slab). The outer part of the head of the bolt is chamfered at 30 degrees just like the nut. Refer to Fig 1 below. The Bolt comprises of the following lengths

a. Shank length = The length 'L' as illustrated in the below figure.
b. Threaded length = The length 'X' as illustrated in the below figure
c. The thickness of the head = 0.8 d

Orthographic Views of the Hexagonal Headed Bolt

1. For the purpose of constructing the orthographic views of the bolt, we place the bolt on the HP in a way that its axis is parallel to both the HP and the VP.

2. We start with the LH or the RH Side View (as the question requires). First we construct the hexagon with 'd' diameter. Then the Chamfer circle, the crest circle and the root circle

3. Take the projections to construct the FV of the bolt.







Exercise - Hexagonal Headed Bolt - 2

Q 1. Draw to scle 1:1, the Front View and LH Side View of a hexagonal headed bolt having threads of specification M30, keeping its axis parallel to the HP and the VP. Take the Shank length of the bolt as 120 mm.