How to Select AccuLock™ S Consumables
Picking AccuLock™ S consumables takes six choices, and most of them follow from two facts: your gun’s power pin and your wire size. This guide walks through each choice in order, so anyone can build a complete parts list without knowing the system ahead of time.
AccuLock S is a front-end consumable system for semi-automatic MIG guns. It covers wire from 0.023″ to 1/8″ (0.6–3.2 mm) and is compatible with BTB Series MIG guns, Miller® MDX™-250 Series MIG guns and S-Gun™ MIG guns.
The parts in the system, from back to front:
- Power pin: Connects the gun to the wire feeder. Matches the feeder brand.
- Power pin cap: Holds the front load liner at the back of the gun. Color-coded to the liner.
- Liner: Guides the wire through the cable. Color-coded by wire size.
- Insulator: Sits on the neck and isolates the front end. Depends on the handle style.
- Diffuser: Threads or slips onto the neck, locks the liner and holds the contact tip.
- Contact tip: Transfers current to the wire. Sized to the wire.
- Nozzle: Directs the shielding gas. Must match the diffuser size.
Before you start
Gather these five facts first. Every choice in this guide depends on at least one of them.
| What you need | Where to find it | Used in |
|---|---|---|
| Gun model and handle style (curved or straight) | Gun label or part number | Insulator |
| Wire diameter | Wire spool label | Contact tip, liner, power pin cap |
| Wire type (steel or aluminum) | Wire spool label | Contact tip |
| Power pin brand (Miller®, Lincoln®, Tweco® #4, Tweco® #5, Euro, OXO™) | Back of the gun or feeder brand | Power pin, power pin cap |
| Cable length (10, 15, 20 or 25 ft) | Gun label or part number | Liner |
You’ll also decide on nozzle preferences (bore size, tip position, copper or brass) based on the joints you weld. Step 3 explains those choices.
Step 1: Choose front load or rear load liner
Choose front load unless you need to keep your existing rear load liner. This decision comes first because it determines which diffusers, power pin parts and liners you can use.
| Front load liner (recommended) | Rear load liner | |
|---|---|---|
| Liner installation | Error-proof: no measuring, trim flush with the back of the power pin | Follows rear load liner instructions (spec sheet SP-BER-RLL) |
| Liner locking and alignment | Locked and concentrically aligned from power pin to contact tip | Not engineered for error-proof liner replacement and flawless wire feeding |
| Diffusers | D-A1, D-A2, DS-A1, DS-A2 | Part numbers ending in -C |
| Power pin and cap | AccuLock S power pin and color-coded cap (Step 6) | Not covered in this guide |
| Best for | New setups and full conversions | Switching tips, nozzles and diffusers without changing the liner |
Converting with a rear load liner? The ALCSK-1 starter kit converts Bernard BTB guns, or select competitor guns, to AccuLock S consumables while keeping a rear load liner.
Step 2: Choose the diffuser and insulator
Pick the diffuser by three things: size, connection style and the liner type from Step 1. The size you choose here locks in your nozzle size in Step 3.
Size: Small diffusers take small nozzles (0.938″ O.D.), which are slimmer for tighter joint access. Large diffusers take large nozzles (1.062″ O.D.), which offer more bore sizes, including 3/4″.
Connection: Thread-on or slip-on. Match the connection your gun’s neck uses.
| Diffuser | Thread-on | Slip-on |
|---|---|---|
| Small, front load liner | DS-A1 | DS-A2 |
| Small, rear load liner | DS-A1-C | DS-A2-C |
| Large, front load liner | D-A1 | D-A2 |
| Large, rear load liner | D-A1-C | D-A2-C |
Diffusers come in packs of 10.
Insulator: Choose by handle style. Insulators come in packs of 5.
| Handle and neck | Insulator |
|---|---|
| BTB curved handle, rotatable or fixed neck | 4623R |
| BTB T Series or C Series straight handle, fixed neck | 402-11 |
Step 3: Choose the nozzle
The nozzle must match the diffuser size from Step 2: small with small, large with large. Then choose bore, tip position and material. Decide now whether you want a tapered nozzle, because it changes the contact tip in Step 4.
Bore: The opening at the front. Smaller bores fit into tighter joints; larger bores give wider shielding gas coverage.
Tip position: Where the contact tip sits relative to the nozzle end: flush (even with the end), recessed (set back 1/8″, 1/4″ or 1/2″) or extended (1/8″ past the end).
Material: Copper or brass.
Tapered nozzles (NST and NT-A3800C) have a narrow front for joint access and require ‘TT’ Series tapered contact tips.
Small nozzles (0.938″ O.D.)
| Part Number | Bore | Tip Position | Material | Tapered |
|---|---|---|---|---|
| NS-A1200B | 1/2″ | Flush | Brass | |
| NS-A1218C | 1/2″ | 1/8″ recess | Copper | |
| NS-A1218B | 1/2″ | 1/8″ recess | Brass | |
| NS-A5800C | 5/8″ | Flush | Copper | |
| NS-A5818C | 5/8″ | 1/8″ recess | Copper | |
| NS-A5800B | 5/8″ | Flush | Brass | |
| NS-A5818B | 5/8″ | 1/8″ recess | Brass | |
| NST-A3800B | 3/8″ | Flush | Brass | Yes |
| NST-A3818B | 3/8″ | 1/8″ recess | Brass | Yes |
| NST-A38XTB | 3/8″ | 1/8″ extension | Brass | Yes |
| NST-A1218B | 1/2″ | 1/8″ recess | Brass | Yes |
Large nozzles (1.062″ O.D.)
| Part Number | Bore | Tip Position | Material | Tapered |
|---|---|---|---|---|
| N-A3400C | 3/4″ | Flush | Copper | |
| N-A3418C | 3/4″ | 1/8″ recess | Copper | |
| N-A3414C | 3/4″ | 1/4″ recess | Copper | |
| N-A3412C | 3/4″ | 1/2″ recess | Copper | No (HD MIG only) |
| N-A3418B | 3/4″ | 1/8″ recess | Brass | |
| N-A3414B | 3/4″ | 1/4″ recess | Brass | |
| N-A5800C | 5/8″ | Flush | Copper | |
| N-A5818C | 5/8″ | 1/8″ recess | Copper | |
| N-A5814C | 5/8″ | 1/4″ recess | Copper | |
| N-A5818B | 5/8″ | 1/8″ recess | Brass | |
| N-A5814B | 5/8″ | 1/4″ recess | Brass | |
| N-A1218C | 1/2″ | 1/8″ recess | Copper | |
| N-A1214C | 1/2″ | 1/4″ recess | Copper | |
| NT-A3800C | 3/8″ | Flush | Copper | Yes |
| NT-A1218C | 1/2″ | 1/8″ recess | Copper | Unconfirmed |
Nozzles come in packs of 10. N-A3412C is only for the Miller® HD (High-Deposition) MIG CV GMAW process.
Step 4: Choose the contact tip
Match the tip to your wire diameter, then pick the series based on your nozzle and wire type. All AccuLock tips are copper, 0.350″ O.D., and torque to 30 in.-lbs. (3.5 Nm).
- Tapered nozzle from Step 3? Use a ‘TT’ Series tip (2.0″ long).
- Aluminum wire? Use an aluminum-specific ‘T’ Series tip.
- Everything else: Use a standard ‘T’ Series tip (1.25″ long).
| Wire Size | ‘T’ Series | ‘TT’ Series (tapered nozzles only) | Aluminum |
|---|---|---|---|
| 0.023″ (0.6 mm) | T-A023CH | TT-A023CH | |
| 0.030″ (0.8 mm) | T-A030CH | TT-A030CH | |
| 0.035″ (0.9 mm) | T-A035CH | TT-A035CH | T-A035AL |
| 0.039″ (1.0 mm) | T-A039CH | TT-A039CH | |
| 0.045″ (1.2 mm) | T-A045CH | TT-A045CH | |
| 3/64″ (1.2 mm) | T-A047AL | ||
| 0.052″ (1.3 mm) | T-A052CH | TT-A052CH | |
| 1/16″ (1.6 mm) | T-A062CH | TT-A062CH | T-A062AL |
| 0.072″ (1.8 mm) | T-A072CH | ||
| 5/64″ (2.0 mm) | T-A078CH | ||
| 3/32″ (2.4 mm) | T-A094CH | ||
| 7/64″ (2.8 mm) | T-A109CH | ||
| 1/8″ (3.2 mm) | T-A125CH |
Tips come in packs of 10. For bulk packs, add -100 (0.030″–3/32″ ‘T’ Series and all aluminum tips) or -1000 (0.030″–0.052″ ‘T’ Series and all aluminum tips) to the part number.
AccuLock S shares its contact tips with Tregaskiss® AccuLock R consumables, so shops running robotic and semi-automatic guns can stock one tip.
Step 5: Choose the front load liner
Find your wire size in the left column, then read across to your cable length. Remember the liner color: the power pin cap in Step 6 must match it. Skip this step if you chose a rear load liner in Step 1.
| Wire Size | Color | 10 ft | 15 ft | 20 ft | 25 ft |
|---|---|---|---|---|---|
| 0.023″–0.030″ (0.6–0.8 mm) | Yellow | LA1A-10 | LA1A-15 | LA1A-20 | LA1A-25 |
| 0.030″–0.035″ (0.8–0.9 mm) | Green | LA2A-10 | LA2A-15 | LA2A-20 | LA2A-25 |
| 0.035″–0.045″ (0.9–1.2 mm) | White | LAD3A-10 | LAD3A-15 | LAD3A-20 | LAD3A-25 |
| 0.045″–1/16″ (1.2–1.6 mm) | Red | LAD4A-10 | LAD4A-15 | LAD4A-20 | LAD4A-25 |
| 5/64″ (2.0 mm) | Blue | LA6A-10 | LA6A-15 | LA6A-20 | LA6A-25 |
| 3/32″ (2.4 mm) | Grey | LA7A-10 | LA7A-15 | LA7A-20 | LA7A-25 |
| 7/64″–1/8″ (2.8–3.2 mm) | Black | LA8A-10 | LA8A-15 | LA8A-20 | LA8A-25 |
Wire size on the line between two colors? 0.030″, 0.035″ and 0.045″ each fall in two ranges. Either liner works; pick one color and use the matching cap.
Step 6: Choose the power pin and power pin cap
Pick the power pin by your feeder brand and wire size, then pick the cap that matches your liner color from Step 5. Both are needed with a front load liner.
Power pin
| Brand | 0.023″–5/64″ (Yellow–Blue) | 3/32″–1/8″ (Grey–Black) |
|---|---|---|
| Miller® | 2200206 | 2200207 |
| Lincoln® | 2200210 | 2200211 |
| Tweco® #4 | 2200150 | 2200151 |
| Tweco® #5 | 2200156 | 2200157 |
| Euro | 2200359 and 2200273 (both required, all sizes) | 2200359 and 2200273 (both required, all sizes) |
| OXO™ | 2200358 | 2200358 |
Power pin cap (match the liner color)
| Liner Color | Miller® | Lincoln® | Tweco® #4 | Tweco® #5 | Euro | OXO™ |
|---|---|---|---|---|---|---|
| Yellow | 2200351 | 2200309 | 2200281 | 2200295 | 2200337 | 2200323 |
| Green | 2200352 | 2200310 | 2200282 | 2200296 | 2200338 | 2200324 |
| White | 2200353 | 2200311 | 2200283 | 2200297 | 2200339 | 2200325 |
| Red | 2200354 | 2200312 | 2200284 | 2200298 | 2200340 | 2200326 |
| Blue | 2200355 | 2200313 | 2200285 | 2200299 | 2200341 | 2200327 |
| Grey | 2200356 | 2200314 | 2200286 | 2200300 | 2200342 | 2200328 |
| Black | 2200357 | 2200315 | 2200287 | 2200301 | 2200343 | 2200329 |
Extra set screws: 2300023P, pack of 10 (1/4-20 x 3/16″ long cup point).
Worked example
A welder has a 400 amp BTB gun with a B Series curved handle, a 15 ft cable and a Miller® power pin, running 0.045″ steel wire. Here’s the complete front load parts list.
| Step | Choice | Part Number |
|---|---|---|
| 1. Liner type | Front load (error-proof installation) | — |
| 2. Diffuser | Large, thread-on, front load | D-A1 |
| 2. Insulator | BTB curved handle | 4623R |
| 3. Nozzle | Large, 5/8″ bore, 1/8″ recess, copper | N-A5818C |
| 4. Contact tip | ‘T’ Series, 0.045″ | T-A045CH |
| 5. Liner | White, 0.035″–0.045″, 15 ft | LAD3A-15 |
| 6. Power pin | Miller®, 0.023″–5/64″ | 2200206 |
| 6. Power pin cap | Miller®, White (matches liner) | 2200353 |
The example assumes a thread-on neck connection and a general-purpose nozzle; a welder with a slip-on neck would use D-A2 instead.
Quick-reference checklist
Run through this list before ordering.
- Liner type chosen (front load or rear load)
- Diffuser matches liner type (-C only for rear load)
- Nozzle size matches diffuser size (small with small, large with large)
- ‘TT’ tip only if the nozzle is tapered
- Aluminum-specific tip if running aluminum wire
- Tip, liner and cap all sized for the same wire
- Liner length matches cable length
- Power pin matches feeder brand and wire range
- Power pin cap color matches liner color
- Insulator matches handle style
Common mistakes
- Mixing sizes: A small nozzle won’t fit a large diffuser, or the reverse.
- ‘TT’ tips in a standard nozzle: ‘TT’ Series tips are only for tapered nozzles.
- Mismatched colors: The power pin cap color must match the liner color.
- Rear load diffuser with a front load liner: Diffusers ending in -C don’t lock the liner, so you lose the error-proof installation.
- Using N-A3412C for standard MIG: It’s only for the Miller® HD MIG process.