Fastener Testing & Quality Control Flashcards
7 cards from real CFS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Fastener Testing & Quality Control flashcards as text
What does magnetic particle inspection (MPI) detect in fasteners?
Answer: Surface and near-surface discontinuities in ferromagnetic materials
MPI reveals surface and near-surface cracks, seams, or laps in ferromagnetic metals by showing leakage flux patterns at discontinuities.
A fastener specification requires 'full-size' mechanical testing. What does this mean?
Answer: The actual fastener (not a machined specimen) is tested
Full-size testing means the actual fastener as manufactured is used as the test specimen, rather than a machined bar cut from the material.
Which characteristic differentiates a 'prevailing torque' nut from a standard hex nut?
Answer: Prevailing torque nuts resist loosening by requiring torque to run on and off the bolt
Prevailing torque nuts incorporate a locking feature—nylon insert, distorted thread, or deformed top—that resists rotation without external locking devices.
When performing a Charpy impact test on fastener material, what property is being evaluated?
Answer: Notch toughness and ability to absorb energy during fracture
The Charpy test measures the energy absorbed when a notched specimen fractures under impact, indicating toughness and resistance to brittle fracture.
What is the purpose of auditing a fastener manufacturer's process control plan during supplier qualification?
Answer: To confirm in-process controls are in place to catch defects before shipment
A process control plan documents the controls, checkpoints, and reactions at each manufacturing step to prevent non-conforming product from reaching the customer.
In an SPC (Statistical Process Control) chart for thread pitch diameter, what does a trend of seven consecutive points above the mean indicate?
Answer: A systematic shift suggesting a process change requiring investigation
Seven consecutive points on one side of the mean (a run) is a Western Electric rule violation, signaling a non-random shift in the process that should be investigated.
Which ASTM standard specifies the requirements for zinc (hot-dip galvanized) coatings on threaded fasteners?
Answer: ASTM A153
ASTM A153 covers zinc coatings applied by hot-dip galvanizing on iron and steel hardware including bolts, nuts, and other fasteners.