LEECO Friction Hinges: Master Specs, Torque Selection Guide & OEM Series Comparison

Q: What's the real difference between Torque Insert and Integrated Torque, and does it matter for my application?

Insert series (TIP, TIM) is a discrete element you press into an existing hinge body — you're adding friction to a structure you've already designed. Integrated series (QM) combines torque mechanism and hinge structure into one unit. For new designs starting from scratch, Integrated typically wins: fewer components, simpler assembly, one part to certify. For retrofit situations where you've already got a hinge housing and need to add friction, Insert is usually the better fit.

Q: Should I always go for the highest cycle life rating?

No. TIM10A and OW10 carry >50,000-cycle ratings — the highest in the catalog — but that's the right answer for high-frequency applications, not a universal default. Calculate your actual expected cycles first, then choose the tier that covers you with reasonable margin. For the majority of consumer electronics and light industrial applications, the 25,000-cycle rating is the right level.

Q: What's the best way to request a sample and actually get useful feedback?

Tell us the application, not just the model number. Include your panel weight, hinge bore diameter, and a rough description of the environment. The more context, the more useful we can be. Standard sample lead time is 5–10 business days for catalog series.

LEECO Technologies Corporation · Engineering Resource

LEECO Friction Hinges: Master Specs, Torque Selection Guide & OEM Series Comparison

LEECO Application Engineering 26 Series · Updated Q1 2025 For Mechanical Engineers & OEM Procurement

Ben Chen · Mechanical Engineer, LEECO Technologies

18 years in friction hinge application engineering. I've reviewed OEM specifications across consumer electronics, medical devices, and industrial automation — long enough to have seen the same mistakes come through the door in different product categories, different decades, and different continents. This guide covers all 26 current LEECO series, but I wrote it for the decisions that actually trip engineers up, not to repeat what's already on the datasheet.

We've reviewed a lot of hinge specifications over the years. The ones that come back to us as field problems almost never involve the wrong torque calculation. They involve the right torque calculation applied to the wrong series — usually because nobody asked the second question.

What a Friction Hinge Actually Does — and Where the Spec Table Stops Telling the Full Story

A friction hinge holds a panel at any angle through controlled internal resistance. No springs, no detents, no user effort. The mechanism is well understood. What's less well understood is that the specification table only describes performance under one set of conditions: room temperature, rated static load, controlled lab cycling.

Real products don't live in labs.

The torque value in the catalog is the holding force at 23°C under a smooth vertical load. Put that same hinge in a product that ships to a customer in northern Finland or southern Malaysia, and the operating conditions are different. Put it in equipment that gets opened fast by an impatient operator rather than gently by a test fixture, and the dynamic load is different. These aren't edge cases — they're normal. And none of them appear in the spec table.

We're not saying the spec table is misleading. It's accurate for what it describes. We're saying it's the starting point, not the ending point. The sections below try to bridge that gap.

From the Field

A few years ago, a customer designing a rugged field terminal came to us with a straightforward BH10 specification. Panel weight: 0.6 kg. Moment arm: 95 mm. Calculated torque: 0.56 Nm, comfortably inside BH10's range. Correct on paper.

What they hadn't told us — because at that point they hadn't thought to mention it — was that the unit was going to be dropped. Not catastrophically, but regularly. Field equipment gets knocked off shelves. The BH10 handles static torque fine. It's not designed to absorb axial shock loading during a 1-metre drop. We switched them to the TIP10 before tooling. That conversation happened only because we asked about the operating environment, not because the spec table flagged anything.

They still use TIP10 in that product line today.

— LEECO Application Engineering, OEM Industrial Program

The three numbers — and the one engineers most often misread

Torque (Nm) is the holding force range. Outer diameter (mm) sets your mechanical fit. Cycle life is the rated open-close operations under lab conditions. Of the three, cycle life is where we see the most errors — not in misreading the number, but in forgetting what the number assumes. It's a minimum under controlled conditions. Temperature, load angle, and cycling speed all affect the real figure. If you're specifying for a high-temperature or high-frequency application, don't assume the rated number transfers directly.

The Most Expensive Assumption

"The torque matches my panel weight calculation, so I'm done." Torque-to-weight matching is necessary. It is not sufficient. We've seen correctly-torqued hinges fail early because nobody checked cycle life against actual usage frequency, or because the operating temperature shifted the effective torque outside the holding range. Get the torque right first. Then check everything else.

What OEM procurement and design engineers each need from this table — and where they diverge

A design engineer is asking: will this hold my panel at the required angle, across the product's full service life, in the actual environment? An OEM procurement manager is asking: is this series available in the quantities I need, on the lead time my schedule requires, and can it be customized if the design shifts in rev B?

Both questions start from the same spec table. The rest of this guide tries to serve both — the engineering sections first, the procurement considerations woven into the series breakdown and FAQ below.

The Full Spec Table — All 26 LEECO Series

Not sure which group to start from? The decision tree below narrows it down in four steps. Then use the full table for the exact numbers.

Torque values are the adjustable range at standard production spec. Models with "/" variants (e.g. QM12/A/B) have sub-variants with minor dimensional or torque differences — ask for variant-specific datasheets if you're comparing them closely. Cycle life is a rated minimum at 23°C, 0.1 Hz cycling, rated load. Temperature note at the bottom of the table.

Product Series	Model Name	Torque Range (Nm)	Outer Diameter (mm)	Cycle Life
Torque Insert Series
Torque Insert	TIP14	3.2 – 14.4	14 mm	> 25,000
Torque Insert	TIP10	0.8 – 6.0	10 mm	> 25,000
Torque Insert	TIM10 / TIM10A	0.4 – 2.4	10 mm	> 50,000
Constant & Integrated Torque Series
Constant Torque	CD20A / CD20B	1.88 – 6.25	32.1 mm	> 10,000
Integrated Torque	QM15	1.84 – 7.32	15 mm	> 25,000
Integrated Torque	QM12 / A / B	0.0 – 4.92	12.7 mm	> 25,000
Integrated Torque	QM10 / A / B / C	0.0 – 4.08	10 mm	> 25,000
Friction Hinge Series
Friction Hinge	QA7	0.88 – 3.24	7 mm	> 25,000
Friction Hinge	BT7A / BT7B	0.32 – 1.08	7 mm	> 25,000
Friction Hinge	TS10 (Tilt & Swivel)	0.75 – 2.5	10 mm	> 25,000
Integrated Friction Series
Integrated Friction	CT10A / B / C	0.72 – 4.08	10 mm	> 25,000
Integrated Friction	QM7A / B / C / D	0.16 – 1.32	7 mm	> 25,000
Special Function Series
Self-Closing Friction	LL7A / LL7B	0.32 – 1.08	7 mm	> 25,000
One Way Friction	OW10	0.5 – 2.0	10 mm	> 50,000
Stainless Steel Series
Stainless Steel	QM10S	0.0 – 6.25	10 mm	> 25,000
Stainless Steel	BH10S	0.38 – 2.50	10 mm	> 25,000
Barrel Hinge Series
Barrel Hinge	BH12	2.25 – 5.63	12 mm	> 25,000
Barrel Hinge	BH10	0.75 – 3.75	10 mm	> 25,000
Barrel Hinge	BH8	0.38 – 1.00	8 mm	> 10,000
Barrel Hinge	BH7	0.45 – 0.75	7 mm	> 10,000
Barrel Hinge	BH6	0.38 – 0.63	6 mm	> 10,000
Barrel Hinge	BH5 / BH5A	0.4 – 0.5	5 mm	> 10,000
Barrel Hinge	BH4 / BH4A	0.085 – 0.176	4 mm	> 10,000
Barrel Hinge	BH3 / BH3A	0.033 – 0.068	3 mm	> 10,000
Barrel Hinge	BH2A / BH2B	0.013 – 0.038	2.5 mm	> 10,000
Integrated Barrel Series
Integrated Barrel	SH10S / SH10L	0.75 – 6.25	10 mm	> 25,000

Cycle life measured at 23°C, rated load, 0.1 Hz. For applications above 60°C, ask us for temperature-adjusted guidance before committing to a series. For applications below -20°C — particularly BH series — see the note in the series breakdown below.

Series by Series: What Each Group Is Actually For

The catalog groups are not arbitrary. Each reflects a different design problem. Here's what that problem is, what the series solves — and, more usefully, where engineers tend to reach for it when something else would have served them better.

Torque Insert series (TIP14, TIP10, TIM10)

This is the right answer when your design already has a hinge structure and you need to add controlled friction to it — the insert element drops into your housing rather than replacing it. TIP14 goes up to 14.4 Nm, which is real structural holding force. TIP10 covers most panel-weight applications in the 0.8–6.0 Nm range. TIM10A is the series we'd reach for if cycle life matters most: >50,000 cycles, the highest in the Insert group.

Over-Specification Warning

TIP14 gets over-specified regularly. Designers see "highest torque" and assume "safest choice." It isn't — a 14 Nm hinge on a panel that only needs 1.5 Nm creates a product that feels broken to end users. The panel won't move when they expect it to. We've had customers come back after user testing complaining about "stiffness problems" that were entirely a specification problem. Match the torque to the actual load. More is not better here.

Barrel Hinge series (BH2A–BH12)

The most frequently specified series in our catalog, and the one with the widest size range — 2.5 mm to 12 mm. BH10 and BH12 are the workhorses: >25,000 cycles, solid torque range, broadly compatible with consumer electronics and instrument housings. The smaller models (BH8 and below) drop to a >10,000-cycle rating.

That 10,000 number is where we see the most consequential mistakes.

BH Series Below -20°C: We Don't Have Enough Data

Our long-term performance data for BH series in sustained sub-zero environments is limited. The catalog specs are measured at 23°C. We know torque increases as temperature drops — lubricant viscosity changes, material contraction affects fit — but the long-term degradation curve for BH series below -20°C is not something we can quote with confidence from accumulated field data.

If your application runs continuously below -20°C, do not go straight to production on BH series without running your own validation test first. We can support you in designing that test. What we won't do is tell you the catalog numbers transfer directly to that environment, because we genuinely don't know that they do.

A Case We Didn't Catch in Time

A diagnostic instrument manufacturer specified BH6 for a battery compartment cover. The cycle life calculation looked fine based on their estimate of 2–3 opens per day in a clinical setting.

What they hadn't modelled was that in some hospital environments, the same instrument gets handed between shift workers who each re-check the battery before use. Actual cycling in those units turned out to be 15–20 times per day. Early units in high-turnover wards started showing torque degradation around month 14. Not catastrophic failure — just loosening, which in a medical instrument erodes user confidence fast.

We switched them to BH8 in the next production revision. The first-batch warranty cost was real, and avoidable.

What changed after that: cycle life verification against actual usage frequency is now a standard checklist item in every medical device consultation we run — not optional, not left to the customer to calculate. Before we issue a sample recommendation for any medical application, we ask for the expected access frequency and run the cycle life math ourselves. That process came directly from this case. The lesson isn't that BH6 is a bad hinge. It's that "typical usage" in clinical environments is almost always higher than designers estimate — and it's our job to catch that before production, not after.

— Ben Chen, Mechanical Engineer

Stainless steel series (QM10S, BH10S)

For corrosive environments: food processing, marine electronics, outdoor enclosures, anything that gets autoclaved. These are the correct choice for those contexts. Not a general premium upgrade.

Stainless Is Not a Quality Tier

We've had procurement managers request stainless across an entire product line because it "sounds more robust." In dry, indoor applications, stainless steel's higher surface hardness can create different wear dynamics against certain housing materials — in some cases worse than the standard series. Stainless is the engineering-correct answer for the right environment. It is not a universal quality signal, and specifying it where you don't need it adds cost and occasionally causes problems.

One thing worth knowing about the QM10S specifically: its torque range runs 0.0 to 6.25 Nm, the widest of any 10 mm series we make. If you need maximum flexibility within a corrosion-resistant footprint, that's your model.

Special function series (LL7, OW10, TS10)

Three series, three distinct motion problems that standard friction hinges don't solve. LL7 self-closes — opens freely, returns under spring action when released. OW10 resists motion in one direction, allows free travel in the other. TS10 combines tilt and swivel in a single 10 mm barrel.

The OW10 is the one most engineers underuse. It solves a class of display-arm and positioning-mount problems that would otherwise require custom dual-hinge brackets — and it does it at >50,000-cycle rating, which is the highest in the special function group. If you're designing a monitor arm that needs to resist vertical creep while allowing horizontal adjustment, this is the answer. Most people don't reach for it because it's not the obvious choice. It should be.

The Solution That Took Three Meetings to Find

A medical device team had spent two design reviews trying to solve a bedside monitor arm problem: the arm needed to hold position vertically but reposition freely side-to-side for nurses. Their prototype used two separate hinges and a custom bracket that added 40 grams and three assembly steps.

Honestly, it took us a while to suggest OW10. Our first instinct was also a dual-hinge approach. It was only when one of our engineers sketched the motion requirement on paper that it became obvious: one OW10, oriented to resist the vertical axis, solved the whole thing. Simpler assembly, lighter, and fewer components to certify for medical use.

We don't tell this story because we eventually got there. We tell it because our first answer was wrong, and it took three conversations to find the right one. That's normal. Get us on a call early.

— LEECO Application Engineering, Medical OEM Program

Still Working on This One

A customer came to us with a QM10 application where the standard symmetric torque wasn't working well — the panel felt fine opening but too heavy to close with one hand, because the load geometry was different in each direction. We recommended switching to an asymmetric torque configuration on the QM10, where resistance is calibrated differently for opening versus closing travel.

They made the change. The one-hand closing problem improved. But the holding torque at mid-angle turned out to be slightly under what the application needed — the asymmetric tuning shifted the torque distribution in a way that exposed a gap we hadn't fully modelled at the time.

We're still working through the revised specification with them. The asymmetric approach is still the right direction for this application — we just haven't landed on the final torque profile yet. I mention it because asymmetric torque is a genuinely useful tool that most OEM engineers don't know is available, and because the honest answer is that dialling it in correctly takes more iteration than symmetric specs do. If your application has direction-dependent load requirements, it's worth the conversation — just start early.

— Ben Chen, Mechanical Engineer

How to Select the Right Torque — The Calculation, and the Part After the Calculation

The torque calculation is not the hard part. Most engineers get it right. Here it is anyway, with the follow-on steps that don't make it into most selection guides.

Calculate minimum required torque

Torque (Nm) = Panel Weight (kg) × 9.81 × Distance from hinge axis to panel centre of gravity (m). Example: 0.8 kg panel, centre of gravity 120 mm from hinge axis: 0.8 × 9.81 × 0.12 = 0.94 Nm. Add 20–30% margin: target ~1.2 Nm. That puts you looking at BT7A, BH10, or QM10 as starting candidates.

Match diameter to your mechanical envelope — but check the full geometry

Outer diameter tells you if the barrel fits the bore. It doesn't tell you whether the barrel length, shaft diameter, or flange geometry will work in your specific housing. At the 10 mm diameter, we have nine series to choose from — TIP10, TIM10, QM10, CT10, OW10, QM10S, BH10, BH10S, SH10. That's where steps 3 and 4 do the narrowing.

Calculate actual cycle life requirement — not assumed usage

Daily access frequency × operating days per year × service life in years. A wall-mounted HMI accessed 5 times per day for 10 years: 18,250 cycles. A 25,000-cycle rating covers that with margin. A factory touchscreen accessed 40 times per shift, three shifts, 300 operating days: 36,000 cycles per year, 360,000 over ten years. A 25,000-cycle hinge in that application will fail. The math takes two minutes. Do it.

Check the operating environment

Temperature range, exposure to moisture or chemicals, shock and vibration loads. This is the step most guides omit entirely — and the one that explains a disproportionate share of the field returns we see. If the answer to any of these is outside normal indoor conditions, call us before finalizing. A 30-minute conversation is cheaper than a production revision.

One Practical Rule

When two series both satisfy your torque and diameter requirements, take the one with the higher cycle life rating. The cost difference at OEM volumes is usually small. The warranty exposure difference is not.

Where These Hinges End Up — and What Each Environment Actually Demands

Industry lists are easy to write and not always useful to read. What matters is what each environment actually demands of the hinge — because the same 10 mm barrel in a laptop feels completely different from the same 10 mm barrel in a food-processing cabinet, and the selection logic is different too.

AIO Computers & Laptop Displays

Tactile feel matters as much as function here. Engineers often focus only on holding torque and miss the opening-feel requirement. Smooth, consistent motion across the full angle range, over 3–5 years of daily use.

Typically: QM10, QM12, CT10, SH10

Medical Devices & Diagnostic Equipment

Cycle life assumptions go wrong here more than anywhere else in the catalog. Clinical usage frequency is almost always higher than designers estimate. Verify before specifying.

Typically: BH3–BH8, QM10S, BH10S

Industrial Enclosures & HMI Panels

Vibration and shock loading are the variables most often missed. Static torque calculations pass, dynamic loading fails. TIP series handles axial shock; standard BH series does not.

Typically: TIP14, TIP10, CD20A/B, QM15

Display Mounts & Monitor Arms

Multi-axis requirements. OW10 is underspecified here more than anywhere else — designers build custom bracket solutions when a single correctly-selected hinge would do the same job.

Typically: TS10, QM15, SH10S/L, OW10

Portable & Handheld Instruments

Housing tolerance is the hidden constraint at small diameters. BH2 and BH3 require tighter bore machining than most housing suppliers expect. Flag this early.

Typically: BH2A–BH6, QM7, LL7

Automotive Interior Panels

Temperature range matters more than in most applications: consistent torque feel from -30°C to +80°C is the real requirement, not just the nominal torque value at room temperature.

Typically: BH10, BH12, TIM10A

Why Choose LEECO — Specific Advantages Over Standard Market Alternatives

There are other friction hinge suppliers. Here's where the differences actually show up in practice, based on what engineers and procurement managers tell us when they switch to LEECO — or when they come back after trying alternatives.

Factor	LEECO	Typical Market Alternative
Torque range per series	QM10S: 0.0–6.25 Nm in a single 10 mm series — widest in class	Narrower per-series ranges; often requires switching series to access full range
Custom torque	Supported as standard OEM program; 4–8 week validation cycle; no minimum order on initial review	Custom work often requires large MOQ commitments upfront; longer lead times
Sample lead time	5–10 business days for catalog series; express available on request	2–6 weeks common; some distributors do not stock full range
Asymmetric torque	Available on QM series — different opening vs. closing resistance in one unit	Rarely available; typically requires custom mechanical solution
Size range	2.5 mm to 32.1 mm OD across 26 series — single-supplier coverage	Most suppliers cover a narrower range; miniature (<5 mm) often a different vendor
Application engineering	Named engineer review included with sampling; cycle life and environment check standard	Distributor support varies; application review often limited to datasheet guidance
Stainless steel options	QM10S and BH10S — full stainless at 10 mm OD with wide torque range	Stainless often only available at higher diameters or with reduced torque range

One clarification worth making: LEECO is not always the lowest-price option on a per-unit basis. For high-volume commodity applications where standard catalog torques are sufficient and the environment is benign, alternatives may undercut on unit price. Where LEECO consistently wins is on total design cost — fewer revision cycles, fewer warranty returns, and the ability to source a wide range of series from a single application engineering contact.

Questions We Actually Get Asked

Not a comprehensive FAQ — just the questions that come up most often in application consultations, answered the way we'd answer them on a call rather than the way they'd appear in a brochure.

What's the real difference between Torque Insert and Integrated Torque, and does it matter for my application?

Insert series (TIP, TIM) is a discrete element you press into an existing hinge body — you're adding friction to a structure you've already designed. Integrated series (QM) combines torque mechanism and hinge structure into one unit. For new designs starting from scratch, Integrated typically wins: fewer components, simpler assembly, one part to certify. For retrofit situations where you've already got a hinge housing and need to add friction, Insert is usually the better fit. The torque ranges overlap considerably, so the decision is mostly about your housing geometry and assembly process, not about performance.

Should I always go for the highest cycle life rating?

No. TIM10A and OW10 carry >50,000-cycle ratings — the highest in the catalog — but that's the right answer for high-frequency applications, not a universal default. A product that will see 6,000 cycles over its service life doesn't need a 50,000-cycle hinge. It adds cost with no engineering benefit. Calculate your actual expected cycles first, then choose the tier that covers you with reasonable margin. For the majority of consumer electronics and light industrial applications, the 25,000-cycle rating is the right level.

Can I get a custom torque value, and when should I ask?

Yes. Custom torque is more common than most OEM buyers realise — we do it regularly. If your required value sits outside the catalog range, or if you need tighter torque consistency than standard production tolerance provides, we can usually accommodate it. What you need to provide: panel weight and moment arm, required holding angle, cycle life target, and operating temperature range. The earlier you raise this, the better — custom validation typically runs 4–8 weeks, and that timeline is much easier to absorb during design than during tooling. Don't leave it until you're close to production.

What are the actual limitations of the small BH series (BH2A, BH3)?

At 2.5 mm and 3 mm outer diameter, the tolerances that matter are in your housing, not the hinge. A bore that's 0.05 mm oversized will affect torque consistency more than almost anything else. We've had customers come back convinced they received inconsistent parts, when the issue turned out to be bore variation in their housing. Request a detailed installation drawing alongside the sample for BH2 and BH3 — it specifies the bore tolerance your machinist needs to hit. If your supplier can't reliably hold that tolerance, either upgrade to BH4 or BH5 and redesign the pocket, or talk to us about your housing process before committing.

How should I think about stainless steel vs. standard, beyond the obvious corrosion argument?

Stainless steel has higher surface hardness than the standard series, which changes the wear dynamic at the interface with your housing material. For most steel or hard anodised aluminium housings, this is fine. For softer plastics or certain aluminium alloys, the wear characteristics are different — not always worse, but different, and worth checking. If your housing material is unusual, tell us before you finalize. The QM10S also has an unusually wide torque range (0.0–6.25 Nm) for a 10 mm series, which makes it useful when you want stainless construction and maximum torque flexibility at the same time.

What's the best way to request a sample and actually get useful feedback?

Tell us the application, not just the model number. When a sample request comes in with only "BH10, qty 5," we send the samples and that's it. When it comes in with "BH10 for a 0.5 kg display cover on a portable test instrument, opens roughly 10 times per day, operating in field environments," we can flag if we think a different series would serve you better — before you've built prototype tooling around the wrong choice. Include your panel weight, hinge bore diameter, and a rough description of the environment. The more context, the more useful we can be. Standard sample lead time is 5–10 business days for catalog series.

Talk to Our Application Engineers

If you're in early design, a 30-minute call to review your application against the spec table saves a lot of revision cycles later. If you're further along and need samples or a datasheet, use the links below. If you're not sure which series is right, that's the most common reason people contact us — and it's exactly what our application team is here to help with.

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