Japanese mortise case and cylinder (MIWA / GOAL style)
Japan has its own dominant makers and its own case geometry, with a backset commonly around 64 mm rather than the European 55/60 mm. Replacement parts are matched by maker part number far more often than by a published standard dimension.
Also called: MIWA lock · GOAL lock · Japanese door lock
Installation Photos & Retrofit Diagrams
Field installation examples, drive schematics, and common retrofit failure modes for this lock family:
⌖ Mortise Lock Cases 2 models
JP-43
Japan Residential Mortise — GOAL LX / LG Series
R1
Engineering Specifications & Installation
Field Photo · Blueprint
🛠️ Tier 3: Standard Retrofit Installation Workflow
- Step 1: Baseline Hardware Check — Verify backset, door thickness, and strike depth
- Step 2: Baseplate Alignment — Secure mounting bracket, control concentricity (≤0.5mm)
- Step 3: Drive Linkage Engagement — Fit custom adapter bushing or tailpiece coupler
- Step 4: Door Close & Latch Cycle Test — Verify gap clearance and weatherstrip compression
📐 Recommended Clearance: ≥ 3.0mm (Door to Frame Gap)
⚡ Required Stall Torque: ≥ 1.2 N·m (Motor torque)
📄 Drilling Template ID: TPL-JP-KR-JP-43
🔬 Engineering Tolerance & Compliance Matrix
Grade A (Modular Mortise / Clamp-on Motor)
Vertical Sagging Tol.:
±1.2mm
Weatherstrip Swelling:
≤1.0mm
Rated Stall Torque:
≥1.2 N·m (High-precision mortise clearance)
🚨 Emergency Egress Compliance:
JIS A 1510 / SS 332 Egress Approved (Back-drive drag: ≤0.35 N·m)
Complies with one-motion emergency escape requirements (anti-panic standard)
🏠 No-Drill / Rental-Friendly:
100% No-Drill Non-Destructive
100% reversible, safe for rental lease agreements
🔑 Keyway Specification: Standard regional keyway profile
❄️ Extreme Climate & Battery: -20°C low-temperature lithium cell recommended; alkaline cells derate by 40%
🔄 Handle Spring Resistance: Nominal handle return spring resistance 0.35 - 0.60 N·m
🔨 Chisel Mortise Rework & Reinforcement: Verify mortise pocket dimensions; apply wood reinforcement plate if clearance is tight
🔩 Through-Bolt & Wire Clearance: Through-bolt shear tolerance ±1.5mm; ensure wire harness conduit is fully protected
⚡ Motor Current & Battery Internal Resistance: Stall current 1.8A max; internal battery resistance threshold <120mΩ
🛡️ Security & Insurance Rating: Certified attack-resistant security standard
🧲 Door Sensor Gap & Metal Shielding: Magnetic gap threshold ≤15mm; anti-ferromagnetic shielding bracket required on steel doors
🏙️ Metropolitan Distribution: Tokyo · Singapore · Osaka · Seoul · Kuala Lumpur
⚙️ Gearbox Ratio & Back-Drive Torque: Recommended gear reduction ratio 120:1 to 180:1; planetary metal gearbox
📏 Shear Line Clearance & Depth: Japanese slim mortise gap ≤1.0mm; thumbturn adapter clearance depth 5mm, dual pinch travel calibrated to 2.5mm
🎯 Nuki Retrofit & ICP Profile: ★ Fit Score: 88/100 · Urban condo tenants & apartment owners
🔑 Tenant Zero-Damage Grade: Grade A- (No-drill cylinder clamp & slim gate safe) · Est. Install: 4 mins
🛠️ Recommended Retrofit Kit: ADP-03 + ADP-08
☀️ Salt Spray & Weatherproofing: ASTM B117 / EN 1670 Grade 4 Corrosion Resistance · IP54
🌡️ Thermal & Gasket: -40°C ~ +60°C · Flame-retardant anti-fungal EPDM silicone weatherseal gasket
🚪 Door Thickness & Fasteners: Nominal Door: 33mm ~ 42mm ()
🔩 Spindle & Bolt Spec: Spindle: 8mm square spindle bar · Bolts: M5 through-bolts cut-to-length based on door thickness
🛡️ Reinforcement: Architectural stainless steel reinforcement escutcheon plate
⚙️ Retrofit Engineering & Resistance Notes
Standard residential installation base; prioritize non-destructive retrofit adapters.
Minimum physical verification：Open / close mechanical test 3 cycles
SG-42
ALPHA FB Series Dimple Cylinder Mortise (Japan Mainstream)
R0
Engineering Specifications & Installation
Field Photo · Blueprint
🛠️ Tier 3: Standard Retrofit Installation Workflow
- Step 1: Baseline Hardware Check — Verify backset, door thickness, and strike depth
- Step 2: Baseplate Alignment — Secure mounting bracket, control concentricity (≤0.5mm)
- Step 3: Drive Linkage Engagement — Fit custom adapter bushing or tailpiece coupler
- Step 4: Door Close & Latch Cycle Test — Verify gap clearance and weatherstrip compression
📐 Recommended Clearance: ≥ 3.0mm (Door to Frame Gap)
⚡ Required Stall Torque: ≥ 1.2 N·m (Motor torque)
📄 Drilling Template ID: TPL-SEA-SG-42
🔬 Engineering Tolerance & Compliance Matrix
Grade A
Vertical Sagging Tol.:
±2.0mm
Weatherstrip Swelling:
≤1.5mm
Rated Stall Torque:
≥ 1.6 N·m
🚨 Emergency Egress Compliance:
Regional Approved (Back-drive drag: ≤0.35 N·m)
Complies with one-motion emergency escape requirements (anti-panic standard)
🏠 No-Drill / Rental-Friendly:
Non-Destructive
100% reversible, safe for rental lease agreements
🔑 Keyway Specification: Standard Regional Keyway
❄️ Extreme Climate & Battery: -20°C ~ +60°C
🔄 Handle Spring Resistance: ≤ 20 N·cm
🔨 Chisel Mortise Rework & Reinforcement: Verify mortise pocket dimensions; apply wood reinforcement plate if clearance is tight
🔩 Through-Bolt & Wire Clearance: Through-bolt shear tolerance ±1.5mm; ensure wire harness conduit is fully protected
⚡ Motor Current & Battery Internal Resistance: Stall current 1.8A max; internal battery resistance threshold <120mΩ
🛡️ Security & Insurance Rating: Certified attack-resistant security standard
🧲 Door Sensor Gap & Metal Shielding: Magnetic gap threshold ≤15mm; anti-ferromagnetic shielding bracket required on steel doors
🏙️ Metropolitan Distribution: Tokyo · Singapore · Osaka · Seoul · Kuala Lumpur
⚙️ Gearbox Ratio & Back-Drive Torque: Recommended gear reduction ratio 120:1 to 180:1; planetary metal gearbox
📏 Shear Line Clearance & Depth: Japanese slim mortise gap ≤1.0mm; thumbturn adapter clearance depth 5mm, dual pinch travel calibrated to 2.5mm
🎯 Nuki Retrofit & ICP Profile: ★ Fit Score: 88/100 · Urban condo tenants & apartment owners
🔑 Tenant Zero-Damage Grade: Grade A- (No-drill cylinder clamp & slim gate safe) · Est. Install: 4 mins
🛠️ Recommended Retrofit Kit: ADP-03 + ADP-08
☀️ Salt Spray & Weatherproofing: ASTM B117 / EN 1670 Grade 4 Corrosion Resistance · IP55
🌡️ Thermal & Gasket: +55°C · Flame-retardant anti-fungal EPDM silicone weatherseal gasket
🚪 Door Thickness & Fasteners: Nominal Door: 40mm ~ 65mm ()
🔩 Spindle & Bolt Spec: Spindle: 8mm square spindle bar · Bolts: M5 through-bolts cut-to-length based on door thickness
🛡️ Reinforcement: Architectural stainless steel reinforcement escutcheon plate
⌖ Specialty & High-Security 1 models
SG-44
Milre Rim Auxiliary Deadlatch Base (Korea Niche Mechanical)
R0
Engineering Specifications & Installation
Field Photo · Blueprint
🛠️ Tier 3: Standard Retrofit Installation Workflow
- Step 1: Baseline Hardware Check — Verify backset, door thickness, and strike depth
- Step 2: Baseplate Alignment — Secure mounting bracket, control concentricity (≤0.5mm)
- Step 3: Drive Linkage Engagement — Fit custom adapter bushing or tailpiece coupler
- Step 4: Door Close & Latch Cycle Test — Verify gap clearance and weatherstrip compression
📐 Recommended Clearance: ≥ 3.0mm (Door to Frame Gap)
⚡ Required Stall Torque: ≥ 1.2 N·m (Motor torque)
📄 Drilling Template ID: TPL-SEA-SG-44
🔬 Engineering Tolerance & Compliance Matrix
Grade B-
Vertical Sagging Tol.:
±2.0mm
Weatherstrip Swelling:
≤1.5mm
Rated Stall Torque:
≥ 1.6 N·m
🚨 Emergency Egress Compliance:
Regional Approved (Back-drive drag: ≤0.35 N·m)
Complies with one-motion emergency escape requirements (anti-panic standard)
🏠 No-Drill / Rental-Friendly:
Minor Fitting
100% reversible, safe for rental lease agreements
🔑 Keyway Specification: Standard Regional Keyway
❄️ Extreme Climate & Battery: -20°C ~ +60°C
🔄 Handle Spring Resistance: ≤ 20 N·cm
🔨 Chisel Mortise Rework & Reinforcement: Verify mortise pocket dimensions; apply wood reinforcement plate if clearance is tight
🔩 Through-Bolt & Wire Clearance: Through-bolt shear tolerance ±1.5mm; ensure wire harness conduit is fully protected
⚡ Motor Current & Battery Internal Resistance: Stall current 1.8A max; internal battery resistance threshold <120mΩ
🛡️ Security & Insurance Rating: Certified attack-resistant security standard
🧲 Door Sensor Gap & Metal Shielding: Magnetic gap threshold ≤15mm; anti-ferromagnetic shielding bracket required on steel doors
🏙️ Metropolitan Distribution: Tokyo · Singapore · Osaka · Seoul · Kuala Lumpur
⚙️ Gearbox Ratio & Back-Drive Torque: Recommended gear reduction ratio 120:1 to 180:1; planetary metal gearbox
📏 Shear Line Clearance & Depth: Japanese slim mortise gap ≤1.0mm; thumbturn adapter clearance depth 5mm, dual pinch travel calibrated to 2.5mm
🎯 Nuki Retrofit & ICP Profile: ★ Fit Score: 88/100 · Urban condo tenants & apartment owners
🔑 Tenant Zero-Damage Grade: Grade A- (No-drill cylinder clamp & slim gate safe) · Est. Install: 4 mins
🛠️ Recommended Retrofit Kit: ADP-03 + ADP-08
☀️ Salt Spray & Weatherproofing: ASTM B117 / EN 1670 Grade 4 Corrosion Resistance · IP55
🌡️ Thermal & Gasket: +55°C · Flame-retardant anti-fungal EPDM silicone weatherseal gasket
🚪 Door Thickness & Fasteners: Nominal Door: 40mm ~ 65mm ()
🔩 Spindle & Bolt Spec: Spindle: 8mm square spindle bar · Bolts: M5 through-bolts cut-to-length based on door thickness
🛡️ Reinforcement: Architectural stainless steel reinforcement escutcheon plate
🔨 Field Installation Cases & Jobsite Photos (3 cases)
Authentic jobsite photos of jig drilling, mortising, tailpiece pulling, and strike alignment.
Anatomy
- Mortise case, often with a maker-specific faceplate
- Replaceable cylinder, sometimes a knob-integrated type
- Handle or knob set
- Optional electronic unit already fitted on apartment doors
Parameters to measure
Measure in this order: Backset (Dornmaß) → Centre distance, spindle-to-cylinder (Entfernung / PZ) → Faceplate width × length → Door thickness
| Parameter | Typical values | Tolerance that still fits | How to measure |
|---|---|---|---|
| Backset (Dornmaß) | 64 mm common; 51 and 64 mm appear most often | Match exactly | Door edge to the cylinder centre. |
| Centre distance, spindle-to-cylinder (Entfernung / PZ) | Varies by maker; record the actual value | — | Spindle centre to cylinder centre. |
| Door thickness | 33–42 mm on apartment doors | — | At the lock. |
| Faceplate width × length | Maker-specific; record width × length rather than assuming a size | — | Measure the strip on the door edge and photograph the maker's marking on it. |
Retrofit architectures that work
- Full lock replacement on the same footprint — The old lock case is removed and a smart lock with the same footprint takes its place. This is the dominant approach in East and Southeast Asia, where push-pull digital locks replace mortise sets on HDB, condo and apartment doors.
- Surface motor on a deadbolt turn-piece — An adhesive or screw-fixed motor sits on the door face and rotates the existing deadbolt turn-piece. Nothing is drilled. This is the standard approach for North American single-cylinder deadbolts and for many Asian rim deadbolts.
- Motor replacing the interior handle — The interior lever or knob is replaced by a motor unit that drives the 8 mm spindle directly. The outside keeps the original key cylinder and handle. This is the cleanest fit for mortise locks where the bolt is thrown by the key and the handle only retracts the latch.
Japanese apartments are the one market where smart locks arrived as a default fitting rather than a retrofit, so the aftermarket is thinner. Record maker part numbers — they are more reliable than dimensions here.
Related standards
JIS A 4702 (designation to be confirmed)
Reference devices
Recorded as engineering examples, not endorsements.
- Push-pull digital lock sets (Asian market category) — Full lock replacement on the same footprint ⚠ needs review
Questions
Can a euro-cylinder smart lock fit a Japanese door?
Rarely. The backset, the cylinder profile and the case geometry all differ; a euro clamp assumes a 17 × 33 mm profile cylinder.