Free sample guideBlock A

Fasteners and Threads

Thread terminology, designations, series and classes of fit, bolt grades and head markings, taps and thread repair, and how preload and torque keep a joint tight.

What the exam tests here

Thread terminology (pitch vs lead), the designation string, classes of fit, thread series, tap-drill formula, bolt grade markings, tap/pin types, and torque/preload. Heavily tested block.

Practice 10 Block A questions freeNo card needed.

On this page

Know these cold

Pitch = distance between adjacent threads; lead = advance per turn. Double-start: lead = 2 × pitch.
¾–10 UNC–2A: ¾ nominal Ø, 10 tpi, UNC series, class 2, A = external (B = internal).
Tap-drill size = nominal diameter − pitch: 1″–8 UNC → 7/8″; M10 × 1.5 → 8.5 mm.
SAE bolt grade = radial slashes + 2: Grade 5 = 3 slashes (120 000 psi), Grade 8 = 6 slashes (150 000 psi).
Taps, by threads chamfered: taper 7–10 (start/through), plug 3–5 (general/blind), bottoming 1–2 (bottom of a blind hole).

Show all 10 high-yield facts

Acme thread: 29° included angle — a positioning screw, not a fastener. NPT tapers ¾″ per foot.
The first engaged thread carries the largest share of the load, roughly a third.
Machine-screw Ø = (number × 0.013) + 0.060 → #6 = 0.138″.
Never loosen with a torque wrench; a jam nut goes between the joint and the main nut.
Taper pin = 1:48 = ¼″ per foot; flat washer ID ≈ 1/32″ over bolt size.

Thread purpose & terms

Threads do	Examples
Transmit power or force	Acme, square, buttress, worm
Control movement	Jack screw
Convey material	Screw conveyor
Hold parts	Bolt, stud, nut, screw
Form a pressure-tight joint	Tapered pipe thread
Measure	V-form (micrometer)

Pitch = distance to the next thread, measured parallel to the axis.
Lead = axial advance per one full turn.
Multiple starts raise lead without weakening the shaft.
Parts: major, minor, nominal and pitch (effective) diameter; crest, root, flank.
Thread angle is 60° on most fasteners.
Right-hand thread recedes clockwise (tightens CW); left-hand is labelled LH.

Show 2 more

A fastener's size is given as its nominal (major) diameter and its length.
Load distribution: the first engaged thread carries the largest share, roughly a third, and each thread after it less.

Lead

Single-start: lead = pitch. Double-start: lead = 2 × pitch

Exam tip

Pitch is the distance between adjacent threads; lead is how far the thread advances in one turn. They are equal only on a single-start thread.

Designation & fit

Read ¾–10 UNC–2A × 1½ lg element by element.

Element	Meaning
¾	Nominal diameter
10	Threads per inch (tpi)
UNC	Thread series
2	Class of fit
A	External thread (B = internal)
1½	Length

Right-hand and Class 2A/2B are assumed unless stated.
Unified classes of fit run 1 to 3 (A = external, B = internal). Metric threads use tolerance grades such as 6g (bolt) and 6H (nut), a separate system.

Class	Fit	Typical use
1	Loosest	Stove and track bolts
2	Average, hand-assembled	Everyday nuts, bolts, cap screws
3	Closest fit, no allowance (still goes together by hand)	Precision work, e.g. ring and shaft nuts

Exam tip

A = external thread, B = internal. Class 2A/2B is the everyday default and is assumed if no class is stated.

Thread series

Series	Angle	Profile	Note
American National (NC / NF / NEF / NS)	60°	Flat crest and root	Interchangeable with Unified
Unified (UNC / UNF / UNEF / UNS)	60°	Rounded root	At 1″: NF = 14 tpi vs UNF = 12 tpi
Acme	29° included	Flat crest and root	Adjusting/positioning screw (lathe lead screw), not a fastener; resists binding better than a square thread
Square	—	Flanks at right angles to the axis	The most efficient power thread (least friction) for jacks and press screws; hard to cut, and wear can't be taken up
Buttress	—	One steep load face, one sloped back face	Heavy thrust in one direction only; the steep face goes toward the load
NPT pipe	—	Tapered ¾″ per foot	The taper seals the joint
ISO metric	60°	Crest = 0.125 × pitch; root = 0.250 × pitch	Sizes 1.6–300 mm

Constant-pitch series	Use
8 tpi	High-pressure pipe flanges, cylinder-head studs
12 tpi	Thin nuts, boiler work
16 tpi	Fine adjusting and bearing-retaining nuts

Dry-seal pipe threads: crests and roots engage first to remove spiral clearance.
Dry-seal threads are marked NPTF and seal on the thread alone, with no tape or dope. Plain NPT seals on its taper but leaves a small spiral leak path at crest and root, so it needs tape or pipe dope.

M8 × 1.25 × 50	Meaning
M	Metric
8	Major diameter (mm)
1.25	Pitch (mm)
50	Length (mm)

Exam tip

Acme = 29° positioning thread, not a fastener. NPT tapers ¾″ per foot to seal. Unified and American National are interchangeable 60° threads.

Fastener types

Fastener	Definition
Bolt	Tightened by a nut; loaded by its nut
Cap screw	Threaded into a tapped hole
Stud	Threaded both ends — coarse end into soft metal, fine end for clamping
Screw	Loaded by its head
Set screw	Holds a hub by its point. On a keyed shaft: on the key, on a flat, or two at 90° — never two at 180°, which only push against each other. Over threads, put a soft brass plug under it so the threads aren't crushed
Retaining ring	Sits in a groove. With ring pliers, squeeze an internal ring closed to pass along a bore, or spread an external ring open to pass over a shaft, then let it snap into the groove

Exam tip

A screw is loaded by its head; a bolt by its nut. A stud's coarse end goes into the soft metal, the fine end takes the clamping nut.

Strength & head markings

The grade is stamped on the head.

SAE grade	Tensile strength	Radial slash marks
2	≈ 510 MPa (74 000 psi) up to ¾″; ≈ 415 MPa (60 000 psi) over ¾″ to 1½″	None
5	≈ 830 MPa (120 000 psi) up to 1″; ≈ 725 MPa (105 000 psi) over 1″	3
8	≈ 1040 MPa (150 000 psi)	6

Imperial bolt grade from head marks

Grade = number of radial slashes + 2

Grade 5 = 3 slashes; Grade 8 = 6 slashes

Metric: a higher stamped class number = stronger (8.8, 10.9, 12.9).
Reading a metric class: the first number × 100 = tensile strength in MPa; the second = yield as tenths of that. 8.8 = about 800 MPa tensile, yielding at 80 % (about 640 MPa). 8.8 ≈ SAE Grade 5; 10.9 ≈ Grade 8.

Bolt / screw head	Feature
Carriage	Round head + square anti-turn shoulder
Hex	Most common — re-grips every 60°
Square	Re-grips every 90°
Cap screw	Hex or socket head

Nut	Feature
Hex	General use
Square	Bigger flats → more torque
Slotted-hex / castellated	Cotter-pin locked
Stover & nylon-insert	Self-locking
Jam	Thin locknut — sits between the joint and the main nut so the main nut takes the load
Cage, clip or rivet nut	Gives a full nut's worth of thread in sheet too thin to tap (a thread tapped in thin sheet strips). A cage nut snaps into a square hole, and its cage stops it turning

Machine-screw diameter

Ø = (number × 0.013) + 0.060

Machine screws ≤ 3/8″, numbered 0–12. #6 = 0.138″

Self-tapping and sheet-metal screws cut their own threads.

Exam tip

Grade = radial slashes + 2: Grade 5 = 3 slashes (120 000 psi), Grade 8 = 6 slashes (150 000 psi). Metric 8.8 < 10.9 < 12.9.

Replacement bolts: the same specification or a stronger one, never a weaker bolt torqued harder. A325 is a high-strength structural bolt (quenched and tempered, about 120 000 psi); A307 is a general-purpose low-carbon bolt (about 60 000 psi). A high-strength bolt that has been heated red to free it has lost its heat treatment: scrap it and fit a new one of the same grade.

Washers & pins

Flat/plain washer spreads the bearing surface (ID ≈ 1/32″ over bolt size).
Split-ring and hi-collar lock washers resist vibration; tooth-lock (external, internal, cone) for extra grip.
Don't put a lock washer on top of a flat washer.

Pin	Use / feature
Cotter	Locking pin through castellated nuts and clevis pins
Clevis / headed	Headed pin retained by a cotter
Taper	1:48 taper = ¼″ per foot
Dowel	Alignment
Shear	Softer or grooved — breaks to protect the machine
Spring / roll	Oversize spring steel
Grooved	Grooves grip the hole
Convenience	Hairpin / quick-lock

Taper pin

Taper 1:48 = ¼″ per foot

Exam tip

Never stack a lock washer on a flat washer. A shear pin is the deliberate weak link — it breaks to protect the machine.

Cutting & repairing threads

Tap	Chamfer	Use
Taper	7–10 threads	Start the thread; through-holes
Plug	3–5 threads	General work; blind holes
Bottoming	1–2 threads	Threads to the bottom of a blind hole

Tap-drill size

TDS = nominal diameter − pitch

1″–8 UNC → 1 − 1/8 = 7/8″; M10 × 1.5 → 8.5 mm

While tapping, back off ~¼ turn to break chips; lubricate except in cast iron.
Broken-tap removal: extractor, punch and hammer, or heat-and-cool — always with eye protection.
Never drill a broken tap: it is hardened high-speed steel, at least as hard as the drill, so the drill only skates, dulls or snaps off in the hole too. A jammed tap can be spark-eroded (EDM) in a machine shop.
Dies cut external threads (4 cutting edges, adjustable split).
Nut won't run on a thread you cut with a split die? The thread is too full: close the die slightly and take another pass. Don't file the crests.
Minor thread damage → tap, die, chaser or file.

Show 5 more

Severe internal damage → drill and tap oversize, plug-weld and re-tap, go deeper with a longer fastener, or install a HeliCoil.
HeliCoil: stronger than the parent metal; diamond-section stainless or phosphor-bronze wire.
Set the HeliCoil top ¼–½ turn below the surface, then snap the tang.
Broken stud: penetrating fluid or heat-cool. If proud → grip with pliers, weld on a nut, or file flats.
Broken stud flush or below → centre-punch, drill a pilot, drive a stud extractor CCW.

Exam tip

Tap drill = nominal diameter − pitch. Back the tap off a quarter turn to break chips, and run cast iron dry.

Preload & torque

Failures: shank breaks, external thread strips, internal thread strips — usually wrong torque or vibration.
Prevent with correct torque values and deeper nuts (more engaged threads).
A screw in a tapped hole needs at least 1½ × its diameter of full thread engaged (a ⅜″ screw → 9/16″): a tapped hole, especially in cast iron, is weaker than a steel nut.

Tensile stage	What happens
Elastic limit	Proof load sits just below yield
Yield point	Permanent set begins
UTS	The fastener breaks

Preload: = the clamping tension put in a fastener as it is tightened, usually set by tightening to a predetermined torque.

Preload method	How
Load-indicating washers	Crush to a gap read with a feeler gauge
Preload-indicating bolts	Wavy flange or spinning cap
Torque nuts / bolts	High clamp from low torque via jacking screws — hardened washer required
Measured elongation	Mic each fastener
Turn-of-the-nut	Snug-tight, then ⅓ to ⅔ of a turn, by bolt length

Torque wrenches: torque-limiting (auto-release), dial-indicating, deflecting-beam, torque multiplier (ratio), hydraulic.
Pick a wrench whose scale puts the target at about 25–75 % of full scale: near the top there is no reserve, and near the bottom it reads poorly. Pull the wrench toward you rather than push it, with good footing, so your hand isn't driven into the machine if something lets go.
Never use a torque wrench to loosen a fastener.
An impact wrench only runs fasteners down — nothing measures the torque it leaves. Snug them, then finish with a torque wrench in a criss-cross (star) pattern, in stages (snug, part torque, full). With an odd number of bolts, skip one each time: seven bolts go 1-3-5-7-2-4-6.
Table values assume new Class 2A/2B threads, lightly lubricated.
Lubrication lowers the torque needed for a given preload — where anti-seize is used, cut the torque to the lubricant maker's figure.
Thread-lockers are anaerobic: liquid while air can reach them, they cure once trapped between metal threads (clean, oil-free threads cure best). Medium strength (removable) suits fasteners taken apart with hand tools; high strength (permanent) needs local heat on the fastener, about 250 °C, and is turned out while still hot.

Watch out

Never loosen a fastener with a torque wrench. Torque tables assume new, lightly lubricated 2A/2B threads — extra lubricant or anti-seize at the same torque over-tightens the bolt.

This is one of SealReady's free sample guides

The full study guide covers every block of the 433A Industrial Millwright exam, with practice questions and a timed mock exam.

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Free sample guideBlock A

Fasteners and Threads

Thread terminology, designations, series and classes of fit, bolt grades and head markings, taps and thread repair, and how preload and torque keep a joint tight.

What the exam tests here

Thread terminology (pitch vs lead), the designation string, classes of fit, thread series, tap-drill formula, bolt grade markings, tap/pin types, and torque/preload. Heavily tested block.

Practice 10 Block A questions freeNo card needed.

On this page

Know these cold

Pitch = distance between adjacent threads; lead = advance per turn. Double-start: lead = 2 × pitch.
¾–10 UNC–2A: ¾ nominal Ø, 10 tpi, UNC series, class 2, A = external (B = internal).
Tap-drill size = nominal diameter − pitch: 1″–8 UNC → 7/8″; M10 × 1.5 → 8.5 mm.
SAE bolt grade = radial slashes + 2: Grade 5 = 3 slashes (120 000 psi), Grade 8 = 6 slashes (150 000 psi).
Taps, by threads chamfered: taper 7–10 (start/through), plug 3–5 (general/blind), bottoming 1–2 (bottom of a blind hole).

Show all 10 high-yield facts

Acme thread: 29° included angle — a positioning screw, not a fastener. NPT tapers ¾″ per foot.
The first engaged thread carries the largest share of the load, roughly a third.
Machine-screw Ø = (number × 0.013) + 0.060 → #6 = 0.138″.
Never loosen with a torque wrench; a jam nut goes between the joint and the main nut.
Taper pin = 1:48 = ¼″ per foot; flat washer ID ≈ 1/32″ over bolt size.

Thread purpose & terms

Threads do	Examples
Transmit power or force	Acme, square, buttress, worm
Control movement	Jack screw
Convey material	Screw conveyor
Hold parts	Bolt, stud, nut, screw
Form a pressure-tight joint	Tapered pipe thread
Measure	V-form (micrometer)

Pitch = distance to the next thread, measured parallel to the axis.
Lead = axial advance per one full turn.
Multiple starts raise lead without weakening the shaft.
Parts: major, minor, nominal and pitch (effective) diameter; crest, root, flank.
Thread angle is 60° on most fasteners.
Right-hand thread recedes clockwise (tightens CW); left-hand is labelled LH.

Show 2 more

A fastener's size is given as its nominal (major) diameter and its length.
Load distribution: the first engaged thread carries the largest share, roughly a third, and each thread after it less.

Lead

Single-start: lead = pitch. Double-start: lead = 2 × pitch

Exam tip

Pitch is the distance between adjacent threads; lead is how far the thread advances in one turn. They are equal only on a single-start thread.

Designation & fit

Read ¾–10 UNC–2A × 1½ lg element by element.

Element	Meaning
¾	Nominal diameter
10	Threads per inch (tpi)
UNC	Thread series
2	Class of fit
A	External thread (B = internal)
1½	Length

Right-hand and Class 2A/2B are assumed unless stated.
Unified classes of fit run 1 to 3 (A = external, B = internal). Metric threads use tolerance grades such as 6g (bolt) and 6H (nut), a separate system.

Class	Fit	Typical use
1	Loosest	Stove and track bolts
2	Average, hand-assembled	Everyday nuts, bolts, cap screws
3	Closest fit, no allowance (still goes together by hand)	Precision work, e.g. ring and shaft nuts

Exam tip

A = external thread, B = internal. Class 2A/2B is the everyday default and is assumed if no class is stated.

Thread series

Series	Angle	Profile	Note
American National (NC / NF / NEF / NS)	60°	Flat crest and root	Interchangeable with Unified
Unified (UNC / UNF / UNEF / UNS)	60°	Rounded root	At 1″: NF = 14 tpi vs UNF = 12 tpi
Acme	29° included	Flat crest and root	Adjusting/positioning screw (lathe lead screw), not a fastener; resists binding better than a square thread
Square	—	Flanks at right angles to the axis	The most efficient power thread (least friction) for jacks and press screws; hard to cut, and wear can't be taken up
Buttress	—	One steep load face, one sloped back face	Heavy thrust in one direction only; the steep face goes toward the load
NPT pipe	—	Tapered ¾″ per foot	The taper seals the joint
ISO metric	60°	Crest = 0.125 × pitch; root = 0.250 × pitch	Sizes 1.6–300 mm

Constant-pitch series	Use
8 tpi	High-pressure pipe flanges, cylinder-head studs
12 tpi	Thin nuts, boiler work
16 tpi	Fine adjusting and bearing-retaining nuts

Dry-seal pipe threads: crests and roots engage first to remove spiral clearance.
Dry-seal threads are marked NPTF and seal on the thread alone, with no tape or dope. Plain NPT seals on its taper but leaves a small spiral leak path at crest and root, so it needs tape or pipe dope.

M8 × 1.25 × 50	Meaning
M	Metric
8	Major diameter (mm)
1.25	Pitch (mm)
50	Length (mm)

Exam tip

Acme = 29° positioning thread, not a fastener. NPT tapers ¾″ per foot to seal. Unified and American National are interchangeable 60° threads.

Fastener types

Fastener	Definition
Bolt	Tightened by a nut; loaded by its nut
Cap screw	Threaded into a tapped hole
Stud	Threaded both ends — coarse end into soft metal, fine end for clamping
Screw	Loaded by its head
Set screw	Holds a hub by its point. On a keyed shaft: on the key, on a flat, or two at 90° — never two at 180°, which only push against each other. Over threads, put a soft brass plug under it so the threads aren't crushed
Retaining ring	Sits in a groove. With ring pliers, squeeze an internal ring closed to pass along a bore, or spread an external ring open to pass over a shaft, then let it snap into the groove

Exam tip

A screw is loaded by its head; a bolt by its nut. A stud's coarse end goes into the soft metal, the fine end takes the clamping nut.

Strength & head markings

The grade is stamped on the head.

SAE grade	Tensile strength	Radial slash marks
2	≈ 510 MPa (74 000 psi) up to ¾″; ≈ 415 MPa (60 000 psi) over ¾″ to 1½″	None
5	≈ 830 MPa (120 000 psi) up to 1″; ≈ 725 MPa (105 000 psi) over 1″	3
8	≈ 1040 MPa (150 000 psi)	6

Imperial bolt grade from head marks

Grade = number of radial slashes + 2

Grade 5 = 3 slashes; Grade 8 = 6 slashes

Metric: a higher stamped class number = stronger (8.8, 10.9, 12.9).
Reading a metric class: the first number × 100 = tensile strength in MPa; the second = yield as tenths of that. 8.8 = about 800 MPa tensile, yielding at 80 % (about 640 MPa). 8.8 ≈ SAE Grade 5; 10.9 ≈ Grade 8.

Bolt / screw head	Feature
Carriage	Round head + square anti-turn shoulder
Hex	Most common — re-grips every 60°
Square	Re-grips every 90°
Cap screw	Hex or socket head

Nut	Feature
Hex	General use
Square	Bigger flats → more torque
Slotted-hex / castellated	Cotter-pin locked
Stover & nylon-insert	Self-locking
Jam	Thin locknut — sits between the joint and the main nut so the main nut takes the load
Cage, clip or rivet nut	Gives a full nut's worth of thread in sheet too thin to tap (a thread tapped in thin sheet strips). A cage nut snaps into a square hole, and its cage stops it turning

Machine-screw diameter

Ø = (number × 0.013) + 0.060

Machine screws ≤ 3/8″, numbered 0–12. #6 = 0.138″

Self-tapping and sheet-metal screws cut their own threads.

Exam tip

Grade = radial slashes + 2: Grade 5 = 3 slashes (120 000 psi), Grade 8 = 6 slashes (150 000 psi). Metric 8.8 < 10.9 < 12.9.

Washers & pins

Flat/plain washer spreads the bearing surface (ID ≈ 1/32″ over bolt size).
Split-ring and hi-collar lock washers resist vibration; tooth-lock (external, internal, cone) for extra grip.
Don't put a lock washer on top of a flat washer.

Pin	Use / feature
Cotter	Locking pin through castellated nuts and clevis pins
Clevis / headed	Headed pin retained by a cotter
Taper	1:48 taper = ¼″ per foot
Dowel	Alignment
Shear	Softer or grooved — breaks to protect the machine
Spring / roll	Oversize spring steel
Grooved	Grooves grip the hole
Convenience	Hairpin / quick-lock

Taper pin

Taper 1:48 = ¼″ per foot

Exam tip

Never stack a lock washer on a flat washer. A shear pin is the deliberate weak link — it breaks to protect the machine.

Cutting & repairing threads

Tap	Chamfer	Use
Taper	7–10 threads	Start the thread; through-holes
Plug	3–5 threads	General work; blind holes
Bottoming	1–2 threads	Threads to the bottom of a blind hole

Tap-drill size

TDS = nominal diameter − pitch

1″–8 UNC → 1 − 1/8 = 7/8″; M10 × 1.5 → 8.5 mm

While tapping, back off ~¼ turn to break chips; lubricate except in cast iron.
Broken-tap removal: extractor, punch and hammer, or heat-and-cool — always with eye protection.
Never drill a broken tap: it is hardened high-speed steel, at least as hard as the drill, so the drill only skates, dulls or snaps off in the hole too. A jammed tap can be spark-eroded (EDM) in a machine shop.
Dies cut external threads (4 cutting edges, adjustable split).
Nut won't run on a thread you cut with a split die? The thread is too full: close the die slightly and take another pass. Don't file the crests.
Minor thread damage → tap, die, chaser or file.

Show 5 more

Severe internal damage → drill and tap oversize, plug-weld and re-tap, go deeper with a longer fastener, or install a HeliCoil.
HeliCoil: stronger than the parent metal; diamond-section stainless or phosphor-bronze wire.
Set the HeliCoil top ¼–½ turn below the surface, then snap the tang.
Broken stud: penetrating fluid or heat-cool. If proud → grip with pliers, weld on a nut, or file flats.
Broken stud flush or below → centre-punch, drill a pilot, drive a stud extractor CCW.

Exam tip

Tap drill = nominal diameter − pitch. Back the tap off a quarter turn to break chips, and run cast iron dry.

Preload & torque

Failures: shank breaks, external thread strips, internal thread strips — usually wrong torque or vibration.
Prevent with correct torque values and deeper nuts (more engaged threads).
A screw in a tapped hole needs at least 1½ × its diameter of full thread engaged (a ⅜″ screw → 9/16″): a tapped hole, especially in cast iron, is weaker than a steel nut.

Tensile stage	What happens
Elastic limit	Proof load sits just below yield
Yield point	Permanent set begins
UTS	The fastener breaks

Preload: = the clamping tension put in a fastener as it is tightened, usually set by tightening to a predetermined torque.

Preload method	How
Load-indicating washers	Crush to a gap read with a feeler gauge
Preload-indicating bolts	Wavy flange or spinning cap
Torque nuts / bolts	High clamp from low torque via jacking screws — hardened washer required
Measured elongation	Mic each fastener
Turn-of-the-nut	Snug-tight, then ⅓ to ⅔ of a turn, by bolt length

Torque wrenches: torque-limiting (auto-release), dial-indicating, deflecting-beam, torque multiplier (ratio), hydraulic.
Pick a wrench whose scale puts the target at about 25–75 % of full scale: near the top there is no reserve, and near the bottom it reads poorly. Pull the wrench toward you rather than push it, with good footing, so your hand isn't driven into the machine if something lets go.
Never use a torque wrench to loosen a fastener.
An impact wrench only runs fasteners down — nothing measures the torque it leaves. Snug them, then finish with a torque wrench in a criss-cross (star) pattern, in stages (snug, part torque, full). With an odd number of bolts, skip one each time: seven bolts go 1-3-5-7-2-4-6.
Table values assume new Class 2A/2B threads, lightly lubricated.
Lubrication lowers the torque needed for a given preload — where anti-seize is used, cut the torque to the lubricant maker's figure.
Thread-lockers are anaerobic: liquid while air can reach them, they cure once trapped between metal threads (clean, oil-free threads cure best). Medium strength (removable) suits fasteners taken apart with hand tools; high strength (permanent) needs local heat on the fastener, about 250 °C, and is turned out while still hot.

Watch out

Never loosen a fastener with a torque wrench. Torque tables assume new, lightly lubricated 2A/2B threads — extra lubricant or anti-seize at the same torque over-tightens the bolt.

This is one of SealReady's free sample guides

The full study guide covers every block of the 433A Industrial Millwright exam, with practice questions and a timed mock exam.

Create a free account See the plans

More free sample guides