ANL‑B3SF51 Bolt Fuse | 40‑650A High Current Automotive Fuse
ANL‑B3 SF51 bolt‑on automotive DC fuse 40‑650A, 32‑48V DC, ISO 8820‑5‑2015 & UL248, for heavy‑duty vehicle, RV, solar battery protection.
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ANL‑B3™ (SF51) Fork Bolt Automobile Fuse High‑Current Bolt‑On DC Fuse for Heavy‑Duty Automotive, RV, Marine & Energy‑Storage Systems
Product Overview
ANL‑B3 (SF51) fork‑bolt automobile DC fuse is a heavy‑duty bolt‑mount high‑current fuse manufactured to ISO 8820‑5‑2015 and UL248 Special Purpose Fuses standards. It adopts UL94‑V0 heat‑resistant thermoplastic housing with visible melting element for fast visual fault inspection. Terminals are high‑conductivity tin‑plated copper alloy with dual M8 bolt mounting, bolt hole spacing 50.8 mm.
The series covers rated current 40A up to 650A, rated voltage 32V /48V DC. Operating temperature range ‑40℃ ~ +125℃, maximum contact‑point temperature allowable up to 150℃. Suited for heavy‑duty vehicles, off‑road machinery, RV camper, marine craft and battery energy‑storage DC circuit over‑current & short‑circuit protection.
Key Features
- ✅ Compliance: ISO 8820‑5‑2015, UL248 Special Purpose Fuses
- ✅ Housing: UL94‑V0 heat‑resistant thermoplastic, visible melting‑element window
- ✅ Terminals: Copper alloy with tin‑plated finish; dual M8 bolt lugs, 50.8 mm hole‑center distance
- ✅ Recommended mounting torque: 12.0 Nm ± 1 Nm
- ✅ Voltage rating: 32V, 48V DC
- ✅ Operating temperature: ‑40℃ ~ +125℃, contact point max 150℃
- ✅ Inverse time‑lag characteristic; short‑circuit protection performance
- ✅ Anti‑vibration fork‑bolt construction for mobile heavy‑duty equipment
Main Dimensions (Unit:mm)
- Overall total length:68.87 mm
- Inner body length:29 mm
- Terminal outer width:19.0 mm
- Terminal inner width:16.3 mm
- Mounting hole diameter:Φ8.6 mm
- Element thickness:1.02 mm
- Element height:9.4 mm
Engineering drawings serve as dimension reference. Please download full datasheet for precise engineering design.
Time‑Current Characteristics
| % of Rating | Opening Time Min / Max (s) | |
| 40A – 250A | 300A-650A | |
| 75 | – / – | 14,400 / ∞ |
| 110 | 14,400 / ∞ | – / – |
| 135 | 120S/1800S | – / – |
| 200 | 1 s / 15s | 1 s / 15 s |
| 350 | 0.300 s / 5 s | 0.500 s / 5s |
| 600 | 0.100 s / 1 s | 0.100 s / 1 s |
Note: Short‑circuit protector only. Some products are under development. Confirm availability with technical team before project selection. Voltage drop test measured under 75% rated current. Typical I²t values are average data obtained from breaking‑capacity pre‑arcing tests. Refer to attached pre‑arcing time‑current curves for complete performance data.
Electrical Ratings
| TYPE | Rating Current(A) | Typ Voltage drop | I2t(A2s) |
| ANL-B3040 | 40A | ≤110mV | 8700 |
| ANL-B3050 | 50A | ≤110mV | 14800 |
| ANL-B3060 | 60A | ≤110mV | 21000 |
| ANL-B3070 | 70A | ≤110mV | 21000 |
| ANL-B3080 | 80A | ≤110mV | 21500 |
| ANL-B3100 | 100A | ≤110mV | 31100 |
| ANL-B3125 | 125A | ≤110mV | 57800 |
| ANL-B3150 | 150A | ≤110mV | 100500 |
| ANL-B3175 | 175A | ≤110mV | 168000 |
| ANL-B3200 | 200A | ≤110mV | 204000 |
| ANL-B3225 | 225A | ≤110mV | 257000 |
| ANL-B3250 | 250A | ≤80mV | 389000 |
| ANL-B3275 | 275A | ≤80mV | 521000 |
| ANL-B3300 | 300A | ≤80mV | 315000 |
| ANL-B3350 | 350A | ≤80mV | 500000 |
| ANL-B3400 | 400A | ≤80mV | 610000 |
| ANL-B3450 | 450A | ≤80mV | 1050000 |
| ANL-B3500 | 500A | ≤80mV | 2050000 |
| ANL-B3550 | 550A | ≤80mV | 2210700 |
| ANL-B3650 | 650A | ≤80mV | 526500 |
Typical Applications
- High‑power car‑audio main circuit heavy‑duty protection
- RV, camper and caravan large‑capacity battery bank DC protection
- Off‑road vehicles, heavy‑duty trucks & construction machinery
- Marine boat high‑current DC power‑distribution systems
- Solar off‑grid battery bank and energy‑storage equipment
- Heavy‑duty 12‑48V DC power & mobile equipment
Installation Notes
- Use M8 fasteners, strictly apply mounting torque: 12.0 Nm ± 1 Nm. Insufficient torque causes contact over‑heating and burnout; excessive torque may crack thermoplastic housing.
- Designed exclusively for DC circuits. Do not apply to AC power systems.
- Check visible melting‑element window after fault occurrence for quick on‑site diagnosis.
- Product performance is affected by ambient temperature and actual working environment. Confirm specifications with technicians for special‑condition projects.
- Some variants are short‑circuit‑only protectors; verify product availability before bulk ordering.
Downloads
Frequently Asked Questions
1: What voltage does ANL‑B3 SF51 fuse support?
A: Standard rated for 32V and 48V DC. It is DC‑only short‑circuit & overload protector.
2: What is the M8 bolt tightening torque requirement?
A: Recommended mounting torque is 12.0 Nm ± 1 Nm. Incorrect torque brings high‑temperature reliability risk.
3: What standards does ANL‑B3 SF51 comply with?
A: Manufactured according to ISO 8820‑5‑2015 and UL248 Special Purpose Fuses specifications.
4: Can ANL‑B3 SF51 be used for RV and solar battery bank?
A: Yes. This high‑current fork‑bolt fuse is widely used for RV, heavy‑duty vehicle and solar battery DC circuit protection.
5: What is the operating temperature range?
A: Operating ambient range ‑40℃ ~ +125℃, maximum allowable contact‑point temperature reaches 150℃.
6: Do you support OEM custom marking and bulk wholesale?
A: Yes, OEM custom marking, project‑volume bulk supply available, please submit inquiry.
Inquiry Information
Submit your inquiry for MOQ confirmation, sample requests, OEM custom‑marking and volume pricing. Fill web contact form or send email for formal quotation and technical documentation support.

