FG Preset Torque Screwdrivers – FAQ & User Guide

Quick Answer

FG preset torque screwdrivers deliver a fixed, repeatable torque using a precision cam-over clutch mechanism. They are ideal for assembly environments where operators repeatedly fasten components at the same torque setting and where over-torque prevention is critical.

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Who This Is For

• Manufacturing & process engineers
• Assembly operators
• Quality & calibration teams
• Aerospace, electronics, and medical device manufacturers
• Production environments requiring poka-yoke fastening control

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When Should You Use This?

Use FG preset torque screwdrivers when:

• Torque must remain fixed and repeatable
• Multiple operators need consistent fastening results
• Fasteners are repeatedly assembled to the same torque
• Over-tightening could damage components or threads
• Process control and quality compliance are important
• You need a tamper-resistant torque setting

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When Should You NOT Use This?

Do not use FG preset screwdrivers when:

• Torque values need frequent adjustment → use an adjustable torque screwdriver
• Torque traceability or data capture is required → use smart torque systems such as ECT/EPT tools
• Very high torque ranges are required → use higher-capacity torque tools or wrenches
• Operators need visible external torque adjustment scales

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How FG Preset Torque Screwdrivers Work

FG preset screwdrivers use a cam-over clutch mechanism:

• Torque builds as the fastener is tightened
• Once the preset torque value is reached, the clutch “cams over” or slips
• Additional torque is prevented from being applied to the fastener

This design minimizes operator influence, prevents over-tightening, and improves fastening consistency.

Result:

• Improved fastening accuracy
• Reduced fastener damage
• Better process repeatability
• Lower operator error rates
• Increased assembly quality control

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Core Features

• Cam-over clutch mechanism for over-torque protection
• Internal preset torque adjustment
• Tamper-resistant design
• Compact ergonomic handle for reduced fatigue
• Designed for repetitive assembly applications
• Precision torque repeatability
• ISO-compliant torque accuracy
• Double locking mechanism to prevent accidental torque changes

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Available Models

The FG Preset Torque Screwdriver Series is available in standard FG, FG-OWC One-Way Clutch, and FG-IFR Impact Free Resetting configurations. Models are offered in multiple torque ranges, label colors, and item numbers to support torque setting identification in manufacturing areas.

Available model families include:

• FG-25z
• FG-50z
• FG-8i
• FG-20i
• FG-40i
• FG-125i
• FG-8i OWC
• FG-20i OWC
• FG-40i OWC
• FG-125i OWC
• FG-8i IFR
• FG-20i IFR
• FG-40i IFR
• FG-125i IFR

Each FG preset torque screwdriver uses a tamper-proof internal adjustment. There is no external adjustment scale. The tool must be preset and verified using a torque analyzer.

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Product Overview

Feature	What Is It?	Advantage	End User Benefit
Cycles Before Calibration	ISO 6789-1:2017 calls for a maximum of 5,000 torque applications	Mountz 4x ISO standards: 20,000 cycles before recalibration	Longer time on the production line; reduces calibration budget and downtime
Consistency	Lifecycle testing of well over 3 million combined torque applications	Confidence every tool meets requirements	Reduces need to replace tools/parts; lower required tool inventory
Cam-Over Technology	Eliminates over-torque; limits the amount of force applied	Eliminates fastener breakage issues; ensures correct torque is applied	Precision and accuracy; error-proofing assembly process; safeguards against fastening failures
Handle Flutes	Sleek 4-flute handle design	Ergonomic	Sleek and comfortable; easy to clean
Needle Thrust Bearing	Rotary bearing to allow rotation between parts	Reduces axial load torque dependency; reduces friction influence on tool output; longer life on internal components	Higher accuracy; durability
Metal End Cap	Eliminates possibility of damage to end cap	Durable and doesn’t strip out like plastic	Fewer parts need replacement; easier to service
Bit Retention / Universal Bit Holder	1/4 inch female hex bit holder that grips any type of bit; patented One Touch bit release	Safe and secure; no band/spring and captive ball to fall out	Better quality and productivity on line; bits don’t fall out or into assembly operation
Locking Mechanism	Double locking mechanism to prevent accidental torque setting change	Avoids torque setting drift	Longer period before recalibration; higher accuracy over time
Preset Tool	Internal torque adjustment mechanism; non-graduated setting torque tool	Tool is set to a designated torque value; correct torque value is consistently applied	Enhances process reliability; improves production quality; increases productivity; reduces scrap rates

Calibration life is 4x ISO standards for the FG-8i, FG-20i, FG-40i, and FG-125i models. Calibration life meets ISO standards for the FG-25z and FG-50z models.

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FG Torque Range Lineup

FG-25z
[3–25 ozf.in / 2–17.7 cN.m]

FG-50z
[10–50 ozf.in / 7.1–35.3 cN.m]

FG-8i
[0.8–8 lbf.in / 9–90 cN.m]

FG-20i
[2–20 lbf.in / 22–226 cN.m]

FG-40i
[4–40 lbf.in / 0.4–4.5 N.m]

FG-125i
[25–125 lbf.in / 2.8–14.1 N.m]

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FG Preset Precision Hand Screwdriver Lineup

Model	Item No.	Torque Range - American	Torque Range - S.I.	Label Color	Drive Size	Length	Weight
FG-25z	076705	3–25 ozf.in	2–17.7 cN.m	Blue	1/4" F/Hex	4.1"	2.8 oz.
FG-25z	076706	3–25 ozf.in	2–17.7 cN.m	Red	1/4" F/Hex	4.1"	2.8 oz.
FG-25z	076707	3–25 ozf.in	2–17.7 cN.m	Green	1/4" F/Hex	4.1"	2.8 oz.
FG-25z	076708	3–25 ozf.in	2–17.7 cN.m	Gold	1/4" F/Hex	4.1"	2.8 oz.
FG-50z	076709	10–50 ozf.in	7.1–35.3 cN.m	Blue	1/4" F/Hex	4.1"	2.8 oz.
FG-50z	076710	10–50 ozf.in	7.1–35.3 cN.m	Red	1/4" F/Hex	4.1"	2.8 oz.
FG-50z	076711	10–50 ozf.in	7.1–35.3 cN.m	Green	1/4" F/Hex	4.1"	2.8 oz.
FG-50z	076712	10–50 ozf.in	7.1–35.3 cN.m	Gold	1/4" F/Hex	4.1"	2.8 oz.
FG-8i	076546	0.8–8 lbf.in	9–90 cN.m	Blue	1/4" F/Hex	5.2"	7.3 oz.
FG-8i	076551	0.8–8 lbf.in	9–90 cN.m	Red	1/4" F/Hex	5.2"	7.3 oz.
FG-8i	076556	0.8–8 lbf.in	9–90 cN.m	Green	1/4" F/Hex	5.2"	7.3 oz.
FG-8i	076561	0.8–8 lbf.in	9–90 cN.m	Gold	1/4" F/Hex	5.2"	7.3 oz.
FG-20i	076547	2–20 lbf.in	22–226 cN.m	Blue	1/4" F/Hex	5.2"	7.3 oz.
FG-20i	076552	2–20 lbf.in	22–226 cN.m	Red	1/4" F/Hex	5.2"	7.3 oz.
FG-20i	076557	2–20 lbf.in	22–226 cN.m	Green	1/4" F/Hex	5.2"	7.3 oz.
FG-20i	076562	2–20 lbf.in	22–226 cN.m	Gold	1/4" F/Hex	5.2"	7.3 oz.
FG-40i*	076548	4–40 lbf.in	0.4–4.5 N.m	Blue	1/4" F/Hex	6.3"	11.5 oz.
FG-40i*	076553	4–40 lbf.in	0.4–4.5 N.m	Red	1/4" F/Hex	6.3"	11.5 oz.
FG-40i*	076558	4–40 lbf.in	0.4–4.5 N.m	Green	1/4" F/Hex	6.3"	11.5 oz.
FG-40i*	076563	4–40 lbf.in	0.4–4.5 N.m	Gold	1/4" F/Hex	6.3"	11.5 oz.
FG-125i*	076549	25–125 lbf.in	2.8–14.1 N.m	Blue	1/4" F/Hex	6.3"	11.5 oz.
FG-125i*	076554	25–125 lbf.in	2.8–14.1 N.m	Red	1/4" F/Hex	6.3"	11.5 oz.
FG-125i*	076559	25–125 lbf.in	2.8–14.1 N.m	Green	1/4" F/Hex	6.3"	11.5 oz.
FG-125i*	076564	25–125 lbf.in	2.8–14.1 N.m	Gold	1/4" F/Hex	6.3"	11.5 oz.

A removable, sliding T-bar is supplied with FG-40i and FG-125i models.

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FG-OWC Preset Precision Hand Screwdriver Lineup

FG-OWC stands for One-Way Clutch. A one-way torque clutch system applies torque in one direction and remains positive, with no torque control, in the opposite direction. This allows the tool to be used for easy screw removal. FG-OWC models are ideal for maintenance and refurbishing applications where undoing or loosening screws is required.

FG-OWC screwdrivers are torque limiting and calibrated in the clockwise direction only.

Model	Item No.	Torque Range - American	Torque Range - S.I.	Label Color	Drive Size	Length	Weight
FG-8i OWC	076586	1.6–8 lbf.in	18–90 cN.m	Blue	1/4" F/Hex	5.2"	7.3 oz.
FG-8i OWC	076591	1.6–8 lbf.in	18–90 cN.m	Red	1/4" F/Hex	5.2"	7.3 oz.
FG-8i OWC	076596	1.6–8 lbf.in	18–90 cN.m	Green	1/4" F/Hex	5.2"	7.3 oz.
FG-8i OWC	076601	1.6–8 lbf.in	18–90 cN.m	Gold	1/4" F/Hex	5.2"	7.3 oz.
FG-20i OWC	076587	2–20 lbf.in	22–226 cN.m	Blue	1/4" F/Hex	5.2"	7.3 oz.
FG-20i OWC	076592	2–20 lbf.in	22–226 cN.m	Red	1/4" F/Hex	5.2"	7.3 oz.
FG-20i OWC	076597	2–20 lbf.in	22–226 cN.m	Green	1/4" F/Hex	5.2"	7.3 oz.
FG-20i OWC	076602	2–20 lbf.in	22–226 cN.m	Gold	1/4" F/Hex	5.2"	7.3 oz.
FG-40i OWC**	076588	4–40 lbf.in	0.4–4.5 N.m	Blue	1/4" F/Hex	6.3"	11.5 oz.
FG-40i OWC**	076593	4–40 lbf.in	0.4–4.5 N.m	Red	1/4" F/Hex	6.3"	11.5 oz.
FG-40i OWC**	076598	4–40 lbf.in	0.4–4.5 N.m	Green	1/4" F/Hex	6.3"	11.5 oz.
FG-40i OWC**	076603	4–40 lbf.in	0.4–4.5 N.m	Gold	1/4" F/Hex	6.3"	11.5 oz.
FG-125i OWC**	076589	25–125 lbf.in	2.8–14.1 N.m	Blue	1/4" F/Hex	6.3"	11.5 oz.
FG-125i OWC**	076594	25–125 lbf.in	2.8–14.1 N.m	Red	1/4" F/Hex	6.3"	11.5 oz.
FG-125i OWC**	076599	25–125 lbf.in	2.8–14.1 N.m	Green	1/4" F/Hex	6.3"	11.5 oz.
FG-125i OWC**	076604	25–125 lbf.in	2.8–14.1 N.m	Gold	1/4" F/Hex	6.3"	11.5 oz.

*A removable, sliding T-bar is supplied with FG-40i OWC and FG-125i OWC models.

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FG-IFR Preset Precision Hand Screwdriver Lineup

FG-IFR stands for Impact Free Resetting. The FG screwdriver design action disengages from the drive when the tool reaches its preset torque value, limiting the torque. Further rotation of the screwdriver handle resets the mechanism for the next torquing operation. FG-IFR models eliminate any slight reaction during resetting.

Model	Item No.	Torque Range - American	Torque Range - S.I.	Label Color	Drive Size	Length	Weight
FG-8i IFR	076651	0.8–8 lbf.in	9–90 cN.m	Blue	1/4" F/Hex	5.2"	7.3 oz.
FG-8i IFR	076656	0.8–8 lbf.in	9–90 cN.m	Red	1/4" F/Hex	5.2"	7.3 oz.
FG-8i IFR	076661	0.8–8 lbf.in	9–90 cN.m	Green	1/4" F/Hex	5.2"	7.3 oz.
FG-8i IFR	076666	0.8–8 lbf.in	9–90 cN.m	Gold	1/4" F/Hex	5.2"	7.3 oz.
FG-20i IFR	076652	2–20 lbf.in	22–226 cN.m	Blue	1/4" F/Hex	5.2"	7.3 oz.
FG-20i IFR	076657	2–20 lbf.in	22–226 cN.m	Red	1/4" F/Hex	5.2"	7.3 oz.
FG-20i IFR	076662	2–20 lbf.in	22–226 cN.m	Green	1/4" F/Hex	5.2"	7.3 oz.
FG-20i IFR	076667	2–20 lbf.in	22–226 cN.m	Gold	1/4" F/Hex	5.2"	7.3 oz.
FG-40i IFR***	076653	4–40 lbf.in	0.4–4.5 N.m	Blue	1/4" F/Hex	6.3"	11.5 oz.
FG-40i IFR***	076658	4–40 lbf.in	0.4–4.5 N.m	Red	1/4" F/Hex	6.3"	11.5 oz.
FG-40i IFR***	076663	4–40 lbf.in	0.4–4.5 N.m	Green	1/4" F/Hex	6.3"	11.5 oz.
FG-40i IFR***	076668	4–40 lbf.in	0.4–4.5 N.m	Gold	1/4" F/Hex	6.3"	11.5 oz.
FG-125i IFR***	076654	25–125 lbf.in	2.8–14.1 N.m	Blue	1/4" F/Hex	6.3"	11.5 oz.
FG-125i IFR***	076659	25–125 lbf.in	2.8–14.1 N.m	Red	1/4" F/Hex	6.3"	11.5 oz.
FG-125i IFR***	076664	25–125 lbf.in	2.8–14.1 N.m	Green	1/4" F/Hex	6.3"	11.5 oz.
FG-125i IFR***	076669	25–125 lbf.in	2.8–14.1 N.m	Gold	1/4" F/Hex	6.3"	11.5 oz.

**A removable, sliding T-bar is supplied with FG-40i IFR and FG-125i IFR models.

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Model Selection Guide

Need a preset screwdriver for very low torque applications?

Choose:

• FG-25z
• FG-50z

These models cover the lowest torque ranges in the FG Preset Torque Screwdriver lineup.

Need a preset screwdriver for low-torque production fastening?

Choose:

• FG-8i
• FG-20i

These models are designed for repeat fastening applications where the same torque value is required across multiple assemblies.

Need a higher torque preset screwdriver?

Choose:

• FG-40i
• FG-125i

These models provide higher torque ranges and include a removable, sliding T-bar.

Need color coding for torque setting identification?

Choose the label color that matches your production or quality control process:

• Blue
• Red
• Green
• Gold

Color coding labels allow for torque setting identification in the manufacturing area.

Need a tool for easy screw removal?

Choose an FG-OWC model:

• FG-8i OWC
• FG-20i OWC
• FG-40i OWC
• FG-125i OWC

FG-OWC models apply torque control in the clockwise direction only and remain positive in the opposite direction for screw removal.

Need to reduce reset reaction during repetitive fastening?

Choose an FG-IFR model:

• FG-8i IFR
• FG-20i IFR
• FG-40i IFR
• FG-125i IFR

FG-IFR models eliminate any slight reaction during resetting.

Which FG model should I select?

Start with these questions:

1. What torque value is required?
2. Does the application require ozf.in, lbf.in, cN.m, or N.m torque units?
3. Is the application standard fastening, screw removal, or repetitive fastening where reset reaction matters?
4. Do you need standard FG, FG-OWC, or FG-IFR functionality?
5. Is color coding needed for torque setting identification?
6. Is a higher torque model with a removable sliding T-bar required?
7. Will the tool need to be preset and verified using a torque analyzer?

The answers to these questions will help determine the correct FG model, torque range, label color, and configuration for the application.

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Setup & Adjustment

Internal Preset Adjustment

FG preset torque screwdrivers use a tamper-proof internal adjustment. They do not have an external adjustment scale.

To set or adjust torque:

1. Use the appropriate adjustment tool.
2. Adjust the internal torque mechanism.
3. Verify the torque setting using a torque analyzer.
4. Seal the end cap with a calibration sticker once the tool is set.

Factory Preset

FG preset torque screwdrivers can also be ordered preset to the application’s required torque value.

Once the tool is set, it is ready to be used in production.

Can Torque Be Changed Later?

Yes. If the preset torque value needs to be changed for a new fastening application, the tool can be adjusted to a new preset torque value and verified using a torque analyzer.

How to Use an FG Preset Torque Screwdriver

1. Confirm the preset torque value.
2. Select the correct bit.
3. Position the tool on the fastener.
4. Apply smooth, steady rotation.
5. Stop once the tool cams over.
6. The cam-over action indicates the preset torque has been reached.

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Decision Guide

FG Preset vs Other Torque Tool Options

Use FG Preset when:

• Torque settings should remain fixed
• Multiple operators perform the same fastening task
• Over-torque prevention is required
• Assembly consistency is critical

Consider other options when:

• Adjustable Screwdriver: Torque changes frequently
• Smart Tools (ECT/EPT): Traceability or data collection required
• Torque Wrenches: Higher torque applications needed

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Use Cases (Real-World Examples)

1. Medical Device Assembly

Problem: Small fasteners were being damaged due to inconsistent operator torque.

Solution: FG preset tools eliminated torque variation and reduced component failures.

2. Electronics Manufacturing

Problem: Operators were unintentionally over-tightening PCB fasteners.

Solution: Cam-over clutch prevented excessive torque and improved quality consistency.

3. Aerospace Assembly

Problem: Critical fasteners required precise repeatable torque.

Solution: FG preset screwdrivers provided repeatability and process control for production assembly.

4. Production Line Standardization

Problem: Operators adjusted torque settings incorrectly between shifts.

Solution: Internal preset configuration prevented unauthorized torque changes.

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Troubleshooting

Issue 1: Torque feels inconsistent

Cause: Tool may be out of calibration.
Solution: Verify torque with analyzer and recalibrate if needed.

Issue 2: Tool slips too early

Cause: Torque set too low or adjustment drift.
Solution: Reset torque using a torque analyzer.

Issue 3: Fasteners are stripping

Cause: Incorrect torque specification for the application.
Solution: Verify engineering torque requirements.

Issue 4: Operator thinks tool is broken

Cause: Operator unfamiliar with cam-over function.
Solution: Train operator that clutch slip indicates target torque reached.

Issue 5: Torque cannot be externally adjusted

Cause: Preset design intentionally prevents external adjustment.
Solution: Use internal adjustment process with proper tools and verification equipment.

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Calibration & Standards

FG preset torque screwdrivers are designed to comply with International Organization for Standardization ISO 6789-1:2017 requirements.

Recommended calibration intervals:

• ISO 6789-1:2017 recommends recalibration after 5,000 torque applications. FG-8i, FG-20i, FG-40i, and FG-125i models are rated for up to 20,000 cycles before recalibration. FG-25z and FG-50z models follow standard ISO calibration interval recommendations. 
• Or according to internal quality requirements

Mountz references extensive lifecycle testing exceeding ISO minimum requirements.

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Integration / Advanced Notes

• No PLC or MES integration (manual hand tool)
• No torque traceability or data capture
• Requires torque analyzer verification for proper setup
• Preset design supports poka-yoke error prevention strategies
• Proper calibration management is essential for accuracy maintenance

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Media & Supporting Content

 

• 
  
  

• FG Preset Torque Screwdriver Product Page
• FG Preset Product Datasheet

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Related Articles / Content

• Mountz Hand Tools Digital Catalog
• The Ultimate Preset Torque Screwdriver for Advanced Process and Quality Control
• How the Right Torque Screwdriver Ensures Consistent Quality
• Guide: Choosing Between Preset and Adjustable Torque Screwdrivers
• Webinar: How To Select a Torque Wrench or Screwdriver to Improve QC Process

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Need Help?

• Contact Applications Engineering for setup guidance
• Speak with Sales for product selection
• Call us:
  • North America:(408) 850-9978
  • International: +44 1428 741756