Ceist Eile

Ceist Eile is in development. Features, questions and prices may change while we refine it.

Subjects · Leaving Cert Engineering

Leaving Cert Engineering: Limits, fits & measurement

How often Limits, fits & measurement comes up on the Engineering papers, every year it was asked, and questions to try.

HL Asked on 6 of the last 9 Higher Level papers, most recently in 2024. most years

OL Asked on 9 of the last 9 Ordinary Level papers, most recently in 2025. banker

June 2028 is the first exam on the new Engineering course. These come from the 2016–2025 papers, so read them as a guide.

Limits, fits & measurement, Higher Level(8 marks)

Quick ones on Limits, fits & measurement.

(a)A hole is dimensioned Ø30 ± 0.06 mm. What is its tolerance?
  1. 0.06 mm
  2. 0.12 mm
  3. 30.06 mm
(b)Metric micrometer: the sleeve shows 12.5 mm and thimble line 23 is on the datum. Reading?
  1. 35.5 mm
  2. 12.523 mm
  3. 12.73 mm
(c)A plug gauge shows a hole is within limits when?
  1. The GO end enters and the NOT GO end does not
  2. The NOT GO end enters and the GO end does not
  3. Both the GO and the NOT GO ends enter
Show the answers

(a) 0.12 mm

(b) 12.73 mm

(c) The GO end enters and the NOT GO end does not

Your turn: Higher Level questions on Limits, fits & measurement.

Higher Level

Asked on 6 of the last 9 Higher Level papers, most recently in 2024. most years

Every paper, year by year

YearWhere it came up
2025Not asked
2024Q1(c)
2023Q1(c)
2022Q1(c)
2021Not asked
2019Q1(g)
2018Q1(f)
2017Q1(f), Q1(k)
2016Not asked

Links open the State Examinations Commission’s paper for that year.

More Limits, fits & measurement questions

Limits, fits & measurement, 3 marks

Hole 25.00–25.04 mm, shaft 24.95–24.98 mm. Minimum clearance?

  1. 0.09 mm
  2. 0.05 mm
  3. 0.02 mm
Show the answer

0.02 mm

Minimum clearance = smallest hole - largest shaft = 25.00 - 24.98 = 0.02 mm. The maximum clearance is 25.04 - 24.95 = 0.09 mm.

Limits, fits & measurement, 2 marks

A gap (snap) gauge is used to check?

  1. Surface roughness, with a fine stylus probe
  2. Shaft diameters, with GO and NOT GO jaws
  3. Hole depths, with GO and NOT GO steps
Show the answer

Shaft diameters, with GO and NOT GO jaws

The shaft must pass the GO gap and be stopped by the NOT GO gap. It is a fast check for batches, with no reading to take.

Ordinary Level

Asked on 9 of the last 9 Ordinary Level papers, most recently in 2025. banker

Every paper, year by year

YearWhere it came up
2025Q7
2024Q7
2023Q7
2022Q7
2021Q7
2019Q7
2018Q7
2017Q1(e), Q7
2016Q7

Links open the State Examinations Commission’s paper for that year.

More Limits, fits & measurement questions

Limits, fits & measurement, 3 marks

A hole is Ø30 ± 0.06 mm. What is its tolerance?

  1. 0.06 mm
  2. 30.06 mm
  3. 0.12 mm
Show the answer

0.12 mm

Tolerance is the whole band: upper limit 30.06 minus lower limit 29.94 = 0.12 mm. The ± figure is only half the tolerance.

Limits, fits & measurement, 2 marks

What is a clearance fit?

  1. The shaft may be larger or smaller than the hole
  2. The shaft is always smaller than the hole
  3. The shaft is always larger than the hole
Show the answer

The shaft is always smaller than the hole

There is always a gap, so the parts slide or turn freely, e.g. a pulley on an axle. Always larger is an interference fit; either way is a transition fit.

Limits, fits & measurement, 3 marks

A hole is Ø20 ± 0.05 mm. What is its largest diameter?

  1. 20.05 mm
  2. 19.95 mm
  3. 0.10 mm
Show the answer

20.05 mm

Upper limit = nominal + 0.05 = 20.05 mm. The lower limit is 19.95 mm, and 0.10 mm is the tolerance.

Other Engineering topics

All of Leaving Cert Engineering