# Leaded inductor

An axial leaded inductor with formed leads. Lead 1 is at the origin, lead 2 is at +X by the pitch, and the leads go down through the board.

- **Horizontal:** the body lies on the board along X, centred between the leads. The leads come out of its ends at the body's axis and bend down.
- **Vertical:** the body stands on the board over lead 1. Lead 2 leaves the top end, turns over and comes down at the pitch.

The series, inductance and tolerance make Fastron's part number, for example MECC-100K (10 µH, ±10 %). The body size follows from them. Fixed choke coils show their colour bands. Suppression coils show their winding under clear insulation foil and have no bands. Vishay Dale's IM inductors are molded cylinders, drawn without bands (below).

| Series | Kind | Body length max | Body Ø max | Lead Ø | Inductance |
|---|---|---|---|---|---|
| MICC | choke | 7 | 3.3 (0.10 to 150 µH), 3.0 (180 to 1000 µH) | 0.5 | 0.10 to 1000 µH |
| SMCC | choke | 9.5 | 4.0 | 0.60 | 0.10 to 10000 µH |
| MECC | choke | 11.0 | 4.5 | 0.6 | 1.0 to 150 µH |
| HCCC | choke | 13 | 4.5 | 0.8 | 0.70 to 33 µH |
| LACC | choke | 14.0 | 4.5 | 0.6 | 1.0 to 56 µH |
| HBCC | choke | 14.5 (1.0 to 18 µH), 12.8 (22 to 100000 µH) | 5.8 | 0.60 | 1.0 to 100000 µH |
| VHBCC | choke | 16.0 | 6.3 (47 µH), 6.0 (the rest) | 0.7 | 10 to 100000 µH |
| XHBCC | choke | 16 | 7.5 | 0.7 | 100 to 100000 µH |
| MISC | suppression | 12.0 (winding 10.0) | 5.0 | 0.80 | 1 to 100 µH |
| MESC | suppression | 24.0 | 7.5 | 0.80 | 3 to 1500 µH |
| 77A | suppression | 26 (30 for 3.9 µH) | 8 to 11 by part number | 0.8 (1.0 for 3.9 µH) | 3.9 to 10000 µH |
| Vishay IM-1 | molded | 5.33 | 2.18 | 0.546 | 0.10 to 100 µH |
| Vishay IM-2 | molded | 6.60 | 2.67 | 0.546 | 0.022 to 1000 µH |
| Vishay IM-4 | molded | 9.78 | 4.19 | 0.686 | 0.15 to 1800 µH |
| Vishay IM-6 | molded | 11.43 | 5.08 | 0.686 | 0.10 to 1000 µH |
| Vishay IM-8 | molded | 14.48 | 5.72 | 0.762 | 1100 to 3600 µH |
| Vishay IM-9 | molded | 14.48 | 6.60 | 0.686 | 68 to 150 µH |
| Vishay IM-10 | molded | 19.05 | 6.35 | 0.864 | 3900 to 10000 µH |

Only inductances a sheet lists are accepted, with the tolerances it offers for them: J ±5 %, K ±10 %, M ±20 %. Vishay's sheet offers ±1, 3, 5, 10 and 20 % for every IM part.

## Source

Fastron's data sheets, one page each, downloaded from Fastron's own site (<https://fastrongroup.com/>, the series' product pages, files under `wp-content/uploads/`). Each sheet's drawing gives the body length (max), body diameter (max) and lead diameter, and its table gives the part numbers, inductances and tolerances:

- MICC, revision date 08 Feb 2021 (`2026/06/MICC.pdf`): 7 max, Ø 3.3 max for R10 to 150 and Ø 3.0 max for 180 to 102, lead Ø 0.5.
- SMCC, revision date 05 Aug 2021 (`2026/06/SMCC.pdf`): 9.5 max, Ø 4.0 max, lead Ø 0.60.
- MECC, revision date 06 Jul 2017 (`2026/06/MECC.pdf`): 11.0 max, Ø 4.5 max, lead Ø 0.6.
- HCCC, revision date 11 Aug 2014 (`2026/06/HCCC.pdf`): 13 max, Ø 4.5 max, lead Ø 0.8.
- LACC, revision date 11 Aug 2014 (`2026/06/LACC.pdf`): 14.0 max, Ø 4.5 max, lead Ø 0.6.
- HBCC, revision date 14 Apr 2025 (`2026/06/HBCC.pdf`): table A max 14.5 for 1.0 to 18 µH and 12.8 for 22 to 100000 µH, Ø 5.8 max, lead Ø 0.60.
- VHBCC, revision date 23 May 2017 (`2026/06/VHBCC.pdf`): 16.0 max, table Ø D max 6.3 for 47 µH and 6.0 for 10 to 33 and 68 to 100000 µH, lead Ø 0.7.
- XHBCC, revision date 31 May 2016 (`2026/06/XHBCC.pdf`): 16 max, Ø 7.5 max, lead Ø 0.7.
- MISC, revision date 27 Apr 2017 (`2026/07/MISC.pdf`): 12.0 max overall, 10.0 max winding, Ø 5.0 max, lead Ø 0.80.
- MESC, revision date 13 Oct 2017 (`2026/07/MESC.pdf`): 24.0 max, Ø 7.5 max, lead Ø 0.80.
- 77A, revision date 26 Jun 2025 (`2026/07/77A.pdf`): dimension table A max, Ø D max and Ø d by part number (26, 8, 0.8 for 5R6 and 100; 26, 9 for 150; 26, 10 for 330; 26, 11 from 400; 30, 8, 1.0 for 3R9), 3 ref at each end.

Vishay Dale, "Inductors, Commercial, Molded, Axial Leaded", IM, document number 34030, revision 28-Aug-13. Vishay no longer hosts it, so this is a distributor's copy, from Online Components: <https://media.onlinecomponents.com/productfiles/mf-da/im.pdf>. The DIMENSIONS table gives inches [millimetres], max and min, for A (diameter), B (length), C (lead length, typ.) and D (lead diameter). This part uses the maximums. The inductance tables (pages 2 to 7) give each model's values.

The colour bands follow the colour code the sheets print (IEC 60062): two digit bands, a multiplier band (gold x0.1, silver x0.01) and a tolerance band (gold J, silver K, none for M). Fastron's Leaded Inductors catalogue (`docs/datasheets/Leaded Inductors.pdf`, revision date 03 Jul 2026, Fig. 7 "Axial preformed") gives its own preformed pitch: MICC 10.0, SMCC 12.5, MECC 15.0, LACC 17.5.

**Proportions, for looks only:**

- The choke's ends taper from twice the lead's diameter to the full diameter over 0.8 x the body's radius. The sheets draw the taper but don't dimension it.
- The four bands are each 0.07 x the body's length wide, centred at 0.30, 0.42, 0.54 and 0.70 of it.
- The suppression coils' foil closes over each end of the winding. Its end length is 1.0 for MISC ((12.0 - 10.0) / 2) and 3 for 77A ("3 ref"), both from the sheets. MESC's sheet doesn't dimension it, so 3 is taken from 77A. The foil is 0.2 thick, and the turns are drawn 0.5 apart and 0.1 deep. The sheets give no wire size.
- The leads bend with a radius of one lead diameter. Vertical lead 2 rises 2.0 above the body before it turns. The body touches the board. The leads end 3.0 below the board by default (`tail`).
- The Vishay IM body's end edges are rounded off by 0.15 x its radius. Vishay's photo shows colour bands, but the sheet gives no marking code, so none are drawn. Its grey is for looks.
- Materials are for looks and a rough mass. The coating and the foil are a plastic, because the sheets name only the core (ferrite or iron dust). The winding is copper and the leads are tinned copper.

The pitch is the board's. Horizontal mounting needs the body length plus two bend radii. Vertical mounting needs lead 2 to clear the body: half its diameter plus half the lead's.

## Catalogue models

The catalogue's `L_Axial_..._Fastron_<series>` models map to these sizes, at the model's own pitch and mounting. Each preset shows one part number of that size: 10 µH where the size has it, otherwise the smallest inductance listed. Measured on the reference models, horizontal and vertical:

- Body length and diameter equal the sheets' maximum for every series and size: MICC 6.96 x 3.3, SMCC 9.49 x 4.0, MECC 10.99 x 4.5, HCCC 13.0 x 4.5, LACC 13.98 x 4.5, HBCC 14.5 and 12.8 x 5.8, VHBCC 16.0 x 6.3, XHBCC 16.0 x 7.5, MISC 12.0 x 5.0, MESC 24.0 x 7.5, 77A 26.0 x 9, 10 and 11, and 30 x 8.
- Their leads are 0.1 thicker than the sheets give: 0.7 for MECC, SMCC and LACC (0.6), 0.9 for HCCC (0.8), 0.8 for VHBCC and XHBCC (0.7), 0.9 for MISC, MESC and 77A (0.8), and 1.1 for 77A 3.9 µH (1.0). HBCC's are 0.8, where the sheet says 0.60. MICC's are 0.5, the same. This part uses the sheets' diameters.
- Their bodies sit 0.1 to 0.2 above the board, where this part's touch it. Their leads also end 3.0 below the board.

The catalogue's Vishay IM-1 and IM-2 models (`L_Axial_L5.3mm_D2.2mm_..._Vishay_IM-1`, `L6.6mm_D2.7mm_..._IM-2`) name the body rounded to 0.1 mm, so a body within 0.05 mm of the sheet's maximum counts as the same. Measured: IM-1 is 5.3 x 2.2 with 0.5 leads, where the sheet gives 5.33 x 2.18 and leads of 0.470 to 0.546. IM-2 is 6.6 x 2.7 with 0.5 leads, where the sheet gives 6.60 x 2.67 and the same leads. Their bodies sit 0.16 to 0.28 above the board. IM-4, IM-6, IM-8, IM-9 and IM-10 have no catalogue model, so they're extra presets lying on the board, at the nearest 2.54 mm grid pitch with room for both bends.

The 77A Ø 10 and Ø 11 models standing at 5.08 mm pitch aren't here: lead 2 would run through the body (5.4 and 5.9 mm from lead 1 are needed). MICC Ø 3.0, VHBCC Ø 6.0 and 77A 26 x Ø 8 have no catalogue model, so they're extra presets lying on the board.

Vishay IM-10-28, IM-10-37 and IM-10-46 (Vishay's document 34035 is gone from vishay.com, and no copy was found), Murata, Bourns, Neosid, Pulse, Würth and EPCOS inductors, and Fastron's radial pin-type coils, aren't here yet; see `COVERAGE.md`.