# Wire form fan guard A wire form fan guard, also called a finger guard. It has concentric steel wire rings, held by four ribs that end in mounting eyes. The eyes sit at the corners of the fan's square mounting-hole pattern. The guard lies on the XY plane, centred on the origin. The eyes are on the XY plane (down), and the rings are raised to the guard's thickness (+Z). `fan` is the fan size. `finish` is the plating: bright nickel chrome, black or stainless. The finish changes only the colour. | Fan | Qualtek part | Hole centres | Eye hole | Outside ring Ø | Centre ring inside Ø | Rings | Ring wire | Rib wire | Thickness | |---|---|---|---|---|---|---|---|---|---| | 30mm | 08346 rev. A | 24 | Ø3.2 +0.3/0 | 21.8 | 9 | 2 | 1.6 | 1.6 | 4.8 REF | | 40mm | 08149 rev. B | 32 | Ø4.0 ±0.2 | 29.53 | 14.2 ±0.5 | 2 | 1.6 | 1.6 | 4.8 REF | | 50mm | 08148 rev. B | 42 | Ø4.2 ±0.2 | 41.1 | 14.2 | 3 | 1.6 | 1.6 | 4.8 | | 60mm | 08147 rev. C | 50 | Ø4.57 +0.3/-0.1 | 53 | 14.2 ±0.5 | 4 | 1.6 | 1.6 | 5.2 REF | | 80mm | 08172 rev. A | 71.37 | Ø4.57 +0.3/-0.1 | 76.2 | 14.2 ±0.5 | 5 | 1.6 | 1.6 | 4.95 REF | | 92mm | 08174 rev. C | 82.42 | Ø4.57 ±0.2 | 89.8 ±1.2 | 14.2 ±0.5 | 6 | 1.6 | 1.6 | 5.0 REF | | 120mm | 08170 rev. B | 104.78 ±0.5 | Ø4.57 +0.3/-0.1 | 115.6 | 14.2 ±0.5 | 8 | 1.8 | 1.8 | 5.66 REF | All values are in millimetres. The wire diameters are ±0.1. ## Source The source is Qualtek Electronics Corp., FAN-S Division, drawings *WIRE FORM FAN GUARD ()*, unit mm, from Qualtek's own site: - `www.qualtekusa.com/Catalog/Fan_Accessories/PDFDrawings/.pdf` for 08149, 08148, 08147, 08172 and 08170. - `www.qualtekusa.com/images/Fan%20Accessories/PDFDrawings/.pdf` for 08346 and 08174. Each drawing gives: - The front view: the hole centres, the eye's hole, the outside ring's diameter over the wire and the centre ring's inside diameter. - The side view: the thickness. - Note 1, the material: C1008 bright basic wire. - Note 2, the finish: bright nickel chrome plating. - Note 4, the ring and rib wire diameters. The 25 mm drawing, 08245 rev. A, is the same kind, and it says OD for the outside ring and ID for the centre ring. The other drawings' Ø over the outside ring and Ø14.2 at the centre ring are read the same way, and their scale agrees. Qualtek's catalogue page *Wire Form Fan Guards - 08 Series* (page 67, a copy hosted by Bossard at ) has the same hole centres, wires, outside rings and thicknesses in its table. It also lists the black (-02) and stainless (-SS) versions. Its DC fan accessories guide (page 71) names these guards for Qualtek's 30 to 120 mm fans. **Read from the drawings, not dimensioned.** - The number of rings is counted on each front view. - The rings between the centre ring and the outside ring aren't dimensioned. The drawings are to scale, and measured on them the rings are evenly spaced (on 08170: 15.8, 29.8, 43.8 … 113.8 between centrelines, 14.0 apart), so the rings here are evenly spaced. **Proportions, for looks only.** - Each rib is straight along its diagonal. The drawings' ribs curve round the centre ring: 4.57 REF apart at the centre on 08170, and 4.0 REF on 08149 and 08147. - Each rib runs just under the rings, overlapping them by 30 % of the two wires' radii, so that each weld is solid. - Each rib then goes down at 45° to the eyes' plane and on to its eye. The jog isn't dimensioned. - The eyes are closed wire loops around the hole. Qualtek's eyes are open hooks. - The welds are spheres 6 % larger than the wire. - On 08148 the eyes are drawn on the axes, which is the same guard turned 45°. Here every size has its eyes on the diagonals. The material is C1008 wire, modelled as `steel-c10` (EN C10, the nearest plain low-carbon steel in the material list) in the finish's colour. The drawings give no weight, so there is no mass check. ## Catalogue models The old catalogue's `circular fan guard 30mm`, `40mm`, `50mm`, `60mm`, `80mm`, `92mm` and `120mm` map to these guards. Their reference models are placeholders. Measured on 2026-11-06, the 120 mm guard model is a 120 x 120 x 2 plate with one Ø86.4 hole. It has no rings and no mounting holes, and it is identical to the same size's grille, duct, plenum, cutter, filter-frame and mounting-pattern models. The name names the standard part, a wire guard for that fan size, so it maps to Qualtek's guard: | 120 mm | Outline | Thickness | Mounting holes | Guard | |---|---|---|---|---| | old model | 120 x 120 plate | 2 | none | one Ø86.4 hole | | Qualtek 08170 | Ø115.6 rings, eyes at 104.78 | 5.66 REF | 4 x Ø4.57 | 8 wire rings, 4 ribs | These models are not mapped: - 25 mm, "no table read yet": Qualtek's 08245 is two slotted eyes on one bar, and the drawing doesn't place the slots. - 140 mm, "no table read yet": the 08 series has no guard for 140 mm fans. - The square grilles, "no table read yet": a square grille is a moulded guard, another part. - The ducts, plenum adapters, cutters, filter frames and mounting-pattern references are placeholders, and their names name no maker's part.