The size of peg is 

Explanation:

The instruments used in chaining in surveying are as follows:

1. Peg: 

• The pegs are generally manufactured of hard timber. One end of the peg is flat and the other edge is pointed.
• The wooden pegs are generally 2.5 cm x 2.5 cm in cross-section and 15-90 cm long.

• The pegs should be firmly driven into the ground such that only 4 cm of the peg is projecting above the ground.

2. Plumb bob:

• Plumb bob is one of the instruments used in chain surveying. Plumb bob is made of steel. It is conical in shape.

•  A plumb bob is used for transferring the points to the ground in case of chaining along a slope.

3. Ranging rods:

• The ranging rods are generally manufactured of steel tubular rods. Sometimes these are made of well-seasoned timber or seasoned bamboo.
• The ranging rods are generally 25 mm in diameter and 2 m in length.
• The ranging rods are divided into bands of 20  cm by painting them black and white or red and white alternately.

• An iron-shoe of 15 mm length is provided at the lower end.

4. Arrows:

• The arrows are manufactured from hardened and tempered steel wire of 4 mm diameter.
• The length of the arrow is kept at 40 cm. one end of the arrow is pointed while at the other end a 5cm diameter ring is formed.

• This ring is formed to facilitate carrying the arrows from one station to another.

5. Chain:

• Chains are the main instruments used in chain surveying. The chains are generally formed with galvanized mild-steel wire. 
• In general, there are 4 types of chains are used in surveying:
  • Metric chain;
  • Surveyors chain or Gunter’s chain;
  • Engineers chain;

  • Revenue Chain.

6. Tapes:

• Among the instruments used in chain surveying for measuring distance, tapes are more accurate than chains.
• Tapes are manufactured of various materials. Tapes are classified into four types;
  • Linen or cloth tape;
  • Metallic tape;
  • Steel tape;
  • Invar tape.