Ion 1.0 / O-Rings & Torque Specs
O-Rings & Torque Specs
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Concrete sizes for every o-ring you’re likely to replace during service. Sizes are given as AS568 dash number/durometer (e.g. 10/70 means AS568-010, 70 durometer) unless noted as an ID measurement — look up the dash number at any o-ring supplier (McMaster-Carr, The O-Ring Store, etc.) for exact ID/OD/cross-section dimensions. Bring these exact numbers to a paintball shop or o-ring supplier rather than guessing off a worn original — a compressed old o-ring reads smaller than its actual spec size.
Removing old o-rings: a 45° hook pick gives the best
angle to get under a seated o-ring and lever it out of its groove without
gouging the surface it seals against. If service has lagged, a dried-out
o-ring can deteriorate and crumble — in the worst case it comes out in
pieces rather than as one ring. Get every fragment out of the groove
before installing the replacement; even a small piece left behind will
keep the new o-ring from sealing.
Decoding Smart Parts' own part numbers: if you're
cross-referencing an original catalog part number, the suffix tells you
the material — UR = Polyurethane, BU/BN
= Buna-N (Nitrile), HN = HNBR (Hydrogenated Nitrile),
VI = Viton (FKM), SI = Silicone,
EP = EPDM.
What color should each material be? Useful for
checking a rebuild kit — or an o-ring already in your marker — against
the Material column above. Confirmed against The O-Ring Store's own
current listings (this site's recommended supplier — see
Services):
- UR (Polyurethane) — clear/translucent.
- BU (Buna-N) — black.
- HN (HNBR) — sold as either black or green, depending on the supplier's inventory at the time. Both are correct — a green o-ring isn't a sign of a wrong part, it's just how this material sometimes ships.
- VI (Viton), if you substitute it for BU per the note further down this page — also typically black.
Barrel
Nothing to service beyond the o-ring — see Thread Sizes & Barrel Compatibility for exact o-ring sizes on stock and multi-piece barrel systems.
Feedneck
| Location | Size | Material | Part # | Notes |
|---|---|---|---|---|
| Feed tube friction o-rings (×3) | 5×25mm ID | BU | ORN02552070BU | Smart Parts calls this part the "feed tube." Remove one or more if a hopper's feedneck fit is too tight. |
Firing assembly / bolt
The bolt itself is identical across Ion 1.0, Ion 2.0, and Ion XE, and its o-ring sizes below apply to all three, per my own hands-on confirmation. The XE’s bolt stop is a physically different part from the 1.0/2.0’s, though — and while its inner o-ring matches, its outer o-ring doesn’t (see the note on that row below). See Rear-Load Bolt for the XE-specific removal procedure.
| Location | Size | Material | Part # | Notes |
|---|---|---|---|---|
| Rear bolt o-ring | 10/70 | UR | ORN01070UR | On the tail of the bolt, seals against the breech. First check for a leak from the rear of the fire chamber. |
| Bolt bumper o-ring | 15/90 | UR | ORN01590UR | Frontmost o-ring on the bolt head. Listed in the Seal Kit table below as "Bolt bumper / ASA seals" — Smart Parts reused the same part for both locations. |
| Bolt middle o-ring | 16×2mm ID | HN | ORN0162070HN | Just behind the bumper o-ring on the bolt head. Check alongside the bolt stop o-rings if the bolt moves forward under pressure without firing. Listed in the Seal Kit table below as "Bolt main seal." |
| Bolt stop o-rings (×2) | 14/70 (inner) and 20/70 (outer) | UR (inner) and BU (outer) | ORN01470UR (inner) and ORN02070BU (outer) | Two different sizes on the same part — don't assume they match. This is the Ion 1.0/2.0/Epiphany size. Ion XE's bolt stop is a different physical part with a different outer o-ring — see the note below the table. |
| Body breech seal o-ring | 20/70 | BU | ORN02070BU | Seals the breech itself, separate from the bolt stop o-rings. |
| Body breech friction o-ring | 22/70 | BU | ORN02270BU | A different size and location from the body breech seal o-ring above — don't confuse the two when ordering. Same size as the Epiphany's. If BU (Buna-N) isn't in stock wherever you're ordering from, Viton (FKM) in the same dash size is a reasonable substitute — better heat and chemical resistance, at a higher cost, and I've used it myself when BU wasn't available. |
| Rear breech o-ring | 17/70 | HN | ORN01770HN | Matches the Epiphany's rear breech o-ring. The Version 2.0 manual's own parts diagram misprints this as 11/70 (ORN01170HN) — the base manual and the Epiphany manual both confirm 17/70 is correct. |
| SFT o-ring | 17/90 | UR | ORN01790UR | In the breech, just in front of the barrel. Common cause of paint breaking when worn, especially in cold weather. Also called the "bolt tip seal" in Smart Parts' own Seal Kit documentation below — same o-ring under a different name, a common inconsistency in paintball parts catalogs from this era, before naming conventions across the industry had settled. |
| Swivel donut o-rings (×2) | 15/70 | UR | ORN01570UR | Underneath the donut, once the retaining snap ring is removed with snap-ring pliers. Rarely needs service — see Firing Assembly for the removal procedure. Listed in the Seal Kit table below as "Fire chamber seals." |
Ion XE's bolt stop o-rings, in detail: the 14/70 (inner)
and 20/70 (outer) sizes above are the Ion 1.0/2.0/Epiphany bolt stop,
Smart Parts #ION111. The Ion XE uses a physically different bolt stop
(#VIB111ASM, confirmed via Tippmann Parts listing it on the Ion XE
Addendum, SP1, and Vibe diagrams). Its inner o-ring still matches at
14/70 — expected, since the inner o-ring seals against the bolt shaft
itself, and the bolt is identical across the whole family. Its outer
o-ring doesn't match, though: per my own hands-on measurement, it
takes 18/70 instead of 20/70, since the outer o-ring
seals against the bolt stop's own body, which differs between the two
parts. Not yet independently confirmed against an official diagram, but
treated as correct pending that — so no manual part number exists yet
for that 18/70 XE-specific variant.
Ball detents
| Location | Size | Material | Part # | Notes |
|---|---|---|---|---|
| Ball detent bore (×2) | 6.35mm diameter | — | — | The hole in the breech each detent (ION108) presses into — measured directly, not a manual-sourced figure. Confirmed identical on an Epiphany body breech. Useful if you're sourcing or designing a replacement detent rather than just replacing the stock part. |
Regulator
| Location | Size | Material | Part # | Notes |
|---|---|---|---|---|
| Adjustment endcap o-ring | 18/90 | UR | ORN01890UR | Around the bottom of the endcap. Check first for a leak from the bottom of the regulator. |
| Piston o-ring — top | 16/70 | UR | ORN01670UR | Listed in the Seal Kit table below as "Regulator piston seal, large." |
| Piston o-ring — bottom | 10/70 | UR | ORN01070UR | Same number as the rear bolt o-ring, but a different part — don't mix up the two when ordering. |
| Regulator o-ring | 15/90 | UR | ORN01590UR | At the top of the regulator body — see the Regulator & ASA page. Same part as the bolt bumper o-ring above. Smart Parts' own manual says a standard CO2 tank o-ring works as a substitute if you're stuck without the exact part. |
Solenoid & hoses
| Location | Size | Material | Part # | Notes |
|---|---|---|---|---|
| Solenoid head o-ring | 9/70 | UR | — | Clear in color. No manual part number found for this one, but my own caliper measurement of the solenoid head post (6.12mm) and the removed o-ring's clear, pliable feel both independently support this size and material — AS568-009's 5.556mm nominal ID stretches onto a 6.12mm post at a normal ~10% (AS568-010's 6.35mm nominal ID would be loose, not gripping, so that size doesn't fit), and "pliable" reads as 70 durometer, not the stiffer 90. |
| 4-mm microline barb seals (×2) | 4×1mm ID | BU | ORN0401070BU | Where the 4-mm hoses attach to the solenoid head. Doesn't typically need routine service. Confirmed via my own manual — resolves the two-numbering ambiguity noted below. |
| Banjo fitting seals (×3) | 1.5×3mm ID | BU | — | Black in color. One per banjo fitting (rear, front, and middle). Replacement fittings should already include this seal. No distinct manual part number found for the seal itself, separate from the fitting it comes with. |
Sourcing replacement microline: both banjo fittings are
standard push-to-connect pneumatic fittings, not a paintball-proprietary
format — confirmed by the official manual's own part numbers
(
Confirmed source, hands-on verified: TECO Technology sells genuine Freelin-Wade polyurethane tubing at both sizes — part 1J-156-27 for the 5/32" line (.157" OD × .093" ID, 100 ft roll) and 1J-157-10 for the 1/8" line (.125" OD × .063" ID, 50 ft roll). I ordered both, received them, and confirmed the tubing itself is correct spec directly — not just matched by catalog numbers, and no brand-specific order minimum either. Nycoil sells matching-spec tubing (catalog parts 76033 for 5/32", 63220 for 1/8") as a fallback if this listing's ever unavailable — not personally verified, but a real catalog match.
Measured lengths on one Ion, cut to length between banjo fittings: rear banjo (5/32") ≈ 19.75mm, front banjo (5/32") ≈ 103.5mm, middle banjo (1/8") ≈ 49mm. Add a few millimeters of tolerance to each when ordering or cutting — trimming a clean end costs a small amount of length.
ELB1032X18PTCBNJ for the 1/8" line,
ELB1032X532PTCBNJ for the 5/32" line). My own OEM
tubing samples read Nycoil/Rectus-Tema Polyurethane, 4mm OD ×
2.5mm ID, 167 PSI max @ 68°F for the 5/32" line, and 1/8" OD ×
1/16" ID (.062") for the 1/8" line, matching my own caliper
measurement.
Confirmed source, hands-on verified: TECO Technology sells genuine Freelin-Wade polyurethane tubing at both sizes — part 1J-156-27 for the 5/32" line (.157" OD × .093" ID, 100 ft roll) and 1J-157-10 for the 1/8" line (.125" OD × .063" ID, 50 ft roll). I ordered both, received them, and confirmed the tubing itself is correct spec directly — not just matched by catalog numbers, and no brand-specific order minimum either. Nycoil sells matching-spec tubing (catalog parts 76033 for 5/32", 63220 for 1/8") as a fallback if this listing's ever unavailable — not personally verified, but a real catalog match.
Measured lengths on one Ion, cut to length between banjo fittings: rear banjo (5/32") ≈ 19.75mm, front banjo (5/32") ≈ 103.5mm, middle banjo (1/8") ≈ 49mm. Add a few millimeters of tolerance to each when ordering or cutting — trimming a clean end costs a small amount of length.
Aftermarket bolts: most aftermarket bolts that follow the
same overall shape as stock reuse the stock o-ring sizes above. Bolts built
from two separate pieces sealed internally to each other — the Firebolt is
the common example — use a different internal o-ring not listed here; check
that specific product's documentation.
Fasteners
| Location | Size | Notes |
|---|---|---|
| Grip frame screws (×2, rear) | 10-32 × 1" | 1/8" hex key. |
| Grip frame screw (front, under barrel) | 10-32 × 1/2" | 1/8" hex key. |
| Grip panel screws | 5/16" length, stock | Shorten to 3/16"–1/4" for thin aftermarket grip panels (Hybrid, Dye, Pro-Touch) — stock-length screws can contact and damage the board through a thinner panel. |
Most other fasteners on the Ion are low-torque, hand-tight-plus-a-quarter-turn fittings rather than precision torque-spec hardware — overtightening is a far more common failure than undertightening.
OEM service kits
Smart Parts also sold two small-parts kits by official SKU, bundling everything above into a single order rather than sourcing o-rings and screws piece by piece.
Seal Kit — Sku 2668 at release — still available today from at least two retailers under SKU ION051 (“ION/EOS/Ion XE Complete Seal Kit”) — every o-ring (plus the body filter and piston seat) needed for a full rebuild:
| Part # | Description |
|---|---|
| ION120 | Body filter |
| ORN01070UR | Regulator piston seal, small |
| ORN01470UR | Bolt stop inner seal |
| ORN01570UR | Fire chamber seals |
| ORN01590UR | Bolt bumper / ASA seals |
| ORN0162070HN | Bolt main seal |
| ORN01670UR | Regulator piston seal, large |
| ORN01770HN | Bolt guide seal |
| ORN01790UR | Bolt tip seal |
| ORN01890UR | Regulator adjuster cap seal |
| ORN02070UR | Body front/stop seals |
| ORN02270BU | Outer body seal |
| ORN02552070BU | Feed tube seals |
| ORN040170BU | Solenoid barb seals |
| IRG103 | Piston seat |
| BND001 | Rubber band |
Part numbers above are as provided in Smart Parts' own official
documentation — kept as-is here rather than silently changed,
even in the two spots below where an independent source disagrees:
- ORN02070UR (Body front/stop seals) — a corrected version of the Ion parts diagram (see Manuals) marks this part as ORN02070BU instead, which matches this page's own Body breech seal and Bolt stop outer o-ring rows above (both Buna-N/BU, not Polyurethane/UR) further up this page.
- ORN040170BU (Solenoid barb seals) — that same corrected diagram lists this part as ORN0401070BU instead, one digit longer. Confirmed via my own Ion manual: the longer number, ORN0401070BU, is correct.
Screw Kit — Sku 2674 at release (current availability unconfirmed) — every screw needed for a full rebuild:
| Part # | Description |
|---|---|
| SCRN0440X0188CO | Regulator safety screw |
| SCRN0448X0250SCO | Trigger adjustment screw |
| SCRN25028X0500SCO | Trigger bottom adjustment screw |
| SCRN0632X0313XTS | Grip screws |
| SCRN1032X0500BS | Bottom line screws |
| SCRN1032X1000BS | Main frame screws |
| SCRN1032X0125SCO | Regulator locking screw |
| SCRN1032X0500VO | Body frame screw |
| PIN009 | Trigger pin |
Diagram from the official Smart Parts Ion Operation and Maintenance Manual.