Free NCCER Industrial Millwright Knowledge Assessment Practice Questions

Sample Practice Questions

Try these 10 sample questions from the NCCER Industrial Millwright Knowledge Assessment practice bank. Each includes the answer and explanation. Continue with the interactive practice above to review the full question set.

1. 1Before a sling is used for the first time on a workday, what inspection is required?

   1. A. Inspect the sling and its fastenings and attachments for defects.
   2. B. Inspect only the lifting hook for visible deformation.
   3. C. Proof test the sling to its rated capacity at the jobsite.
   4. D. Check only the load weight against the crane chart.

   Answer: A

   Explanation: OSHA states, "Each day before being used, the sling and all fastenings and attachments shall be inspected for damage or defects by a competent person designated by the employer." The daily check includes the sling and its connections, not just the hook or load chart.

   Reference: OSHA 29 CFR 1910.184, Slings — 1910.184(d), Inspections

2. 2What is the primary load direction for which a radial ball bearing is designed?

   1. A. A load along the shaft axis
   2. B. A load perpendicular to the shaft axis
   3. C. A pure torsional load about the shaft
   4. D. A bending moment without radial force

   Answer: B

   Explanation: Timken states, "Although radial ball bearings are designed primarily to support a radial load, they perform relatively well under thrust or combined radial and thrust load conditions." The primary design load is radial, perpendicular to the axis.

   Reference: Timken Engineering Manual — Bearing Selection Process, Radial Ball Bearings, page 11

3. 3What makes an O-ring application dynamic rather than static?

   1. A. The sealed parts move relative to one another.
   2. B. The sealed parts are held by threaded fasteners.
   3. C. The O-ring is compressed by a cover.
   4. D. The gland is exposed to a fixed pressure.

   Answer: A

   Explanation: Parker states, "If the machine parts being sealed move relative to one another, the O-ring acts as a dynamic seal." Relative motion is the deciding condition.

   Reference: Parker O-Ring Handbook — 2.1 Definition of design, page 8

4. 4Before grouting a steel equipment baseplate with SikaGrout®-110 AN, how should its steel contact surfaces be prepared?

   1. A. Leave a thin oil film to ease later removal.
   2. B. Remove dirt, oil, grease, and other contaminants.
   3. C. Wet the steel until standing water is visible.
   4. D. Roughen the steel to the concrete CSP range.

   Answer: B

   Explanation: The product sheet states, "Steel surfaces must be free of dirt, oil, grease, or other contaminants." That preparation addresses the steel surface before baseplate grouting; the concrete SSD and CSP requirements are separate.

   Reference: SikaGrout®-110 AN Product Data Sheet — page 2, Surface Preparation—Baseplate Grouting, item 1

5. 5A bearing application must remove substantial operating heat through its lubricant. Which lubrication choice does SKF identify for that requirement?

   1. A. Grease replenished more often to increase heat flow.
   2. B. Circulating oil to carry heat away from the bearing.
   3. C. A higher grease fill with no purge path.
   4. D. Grease with a thicker consistency grade only.

   Answer: B

   Explanation: SKF lists "heat removal via circulating oil is required" among exceptions to the usual grease choice. When lubricant heat removal is a specified requirement, circulating oil addresses it.

   Reference: SKF Rolling Bearings Catalogue, Lubrication — page 110, Selecting grease or oil, exceptions

6. 6At a motor-driven pump, what is the coupling's mechanical connection?

   1. A. It joins the motor drive shaft to the pump driven shaft.
   2. B. It supports the pump shaft in place of its radial bearings.
   3. C. It seals the pump shaft where it exits the casing.
   4. D. It locates the motor and pump casings on the baseplate.

   Answer: A

   Explanation: Fluke states, "The pump coupling connects the drive shaft from the motor and the driven shaft of the pump." Alignment therefore concerns the axes of those coupled rotating shafts.

   Reference: Fluke: How to Check Pump Coupling Alignment — Introduction, coupling function

7. 7Which device combines particle filtering and working-pressure regulation in a compressed-air service unit?

   1. A. Filter regulator
   2. B. Water separator
   3. C. Coalescing filter
   4. D. Air reservoir

   Answer: A

   Explanation: Festo states, "Filter regulators combine a compressed air filter and a pressure control valve in one device". The other components perform different preparation or storage functions.

   Reference: Festo Filter regulator — Filter regulator, introductory description

8. 8A sling is physically intact, but its identification marking is illegible. What is the appropriate decision before lifting?

   1. A. Use it if its material and diameter are known.
   2. B. Use it only with a vertical hitch.
   3. C. Do not use it until it has legible identification markings.
   4. D. Derate it to half the apparent rated capacity.

   Answer: C

   Explanation: The identification requirement is independent of visible sling condition: "Employers must not use slings without affixed and legible identification markings." Guessing or derating does not restore a known rating.

   Reference: OSHA 29 CFR 1910.184, Slings — 1910.184(c)(14), Safe operating practices

9. 9A single-row angular-contact ball bearing supports substantial thrust in which direction?

   1. A. One axial direction
   2. B. Both axial directions equally
   3. C. Only the radial direction
   4. D. Only the circumferential direction

   Answer: A

   Explanation: Timken says, "Single-row, angular contact ball bearings are designed for combination loading with high thrust capacity in one direction". An opposed arrangement would be needed when thrust reverses.

   Reference: Timken Engineering Manual — Bearing Selection Process, Angular Contact Ball Bearings, page 12

10. 10A radial O-ring is at risk of being forced into an oversized clearance gap. Which component addresses that extrusion risk?

    1. A. A back-up ring
    2. B. A wiper ring
    3. C. A lantern ring
    4. D. A gland follower ring

    Answer: A

    Explanation: Parker states, "Back-up rings can be used to protect radially-deformed O-Rings against expected extrusion." The ring supports the O-ring at the gap.

    Reference: Parker O-Ring Handbook — 2.1 Definition of design, page 8, clearance gap