SMC MHS3-32D 3-Finger Parallel Air Gripper 32 mm

Three fingers for self-centring round parts

MHS3-32D is a double-acting three-finger parallel air gripper from the SMC MHS3 series. Three fingers at 120 degrees close together on the centre line, which centres round workpieces such as shafts, bushings, bottle necks and tube sections without a separate locating step. That centring is the main reason to choose a 3-finger unit over the two-finger MHZ2 type when the parts are cylindrical.

In the code MHS3 is the series with three fingers, 32 is the bore in mm and D is double acting; the MHS3 series covers bores 16, 20, 25, 32, 40, 50, 63, 80, 100 and 125 mm, all double acting. No auto-switch letters are appended, so the gripper is ordered without switches although it carries a magnet.

Technical specifications

Where the 32 mm size sits in the range

Gripping force climbs steeply with bore: 42 N at the 25 mm bore, 74 N at 32 mm, 118 N at 40 mm and 187 N at 50 mm for external grip. The diameter stroke also doubles between the 16 and 32 mm sizes (4 mm to 8 mm), which defines how much variation in part diameter one set of finger attachments can absorb. If the part size varies more than the stroke allows, a longer-stroke member of the family is needed; the catalogue lists an MHSL3 long-stroke type for some bores that has opening and closing stroke more than twice the standard.

Finger attachments are made by the user, so the effective gripping point L and the finger weight both change the real force and the allowable moment; follow the selection procedure in the catalogue before final choice.

Application and installation points

Use for turned parts, caps, sleeves and cylindrical components handled by robots and pick-and-place heads. Mount through the tapped holes or knock-pin positions shown in the dimensions, keep the supply air filtered, and fit speed controllers so that finger closing does not shock the part. For auto-switch use with the 32 to 125 mm sizes the catalogue says the mounting brackets are supplied with a gripper ordered with a switch; if the switch is ordered separately the BMG2-012 bracket is required.

Documents and quotation

The SMC catalogue linked at the end of this page gives the how-to-order, gripping-force data and dimensions for MHS3. Confirm the finger geometry, workpiece diameter range and switch needs before ordering. More automation parts are under Pneumatic Cylinders. Seven Star LLC is an independent supplier and will quote the exact code.

How the MHS3-32D Works: Wedge Cam Construction

The MHS3-32D uses SMC’s wedge cam mechanism. When air is supplied, the piston moves axially and drives a cam whose angled faces engage the three fingers. The axial force of the piston is converted into radial finger motion, so all three fingers move towards or away from the centre at the same time. This construction is what allows a relatively high gripping force from a compact, short body, and it gives the self-centring action that makes three-finger grippers so useful for round and hexagonal parts.

Because the unit is double acting, both the closing (external grip) and opening (internal grip) strokes are powered. External grip clamps the outside of a shaft or cap; internal grip expands the fingers inside a bore, ring or tube. The piston carries a magnet as standard, so solid-state auto switches can be added at any time to monitor finger position.

MHS3 Series Range at a Glance

Gripping forces are effective values at 0.5 MPa with gripping point L = 30 mm for the 32 to 63 mm sizes (L = 20 mm for 16 to 25 mm).

MHS3-32D Selection & Ordering Guide

• Series and fingers: MHS3 = parallel type, 3 fingers.
• Bore: 32 = 32 mm.
• Action: D = double acting (the only standard action; single acting is a made-to-order -X84 option for 16 to 63 mm).
• Port thread: for 32 to 63 mm bores the standard (Nil) is M thread; Rc, NPT and G port threads (Nil/TN/TF) apply to the 80 to 125 mm sizes.
• Auto switch: Nil = without switch (built-in magnet), or D-M9N, M9P, M9B and the 2-colour M9□W types, with 1 pc. (S) or 2 pcs. (Nil).

Selection should follow SMC’s procedure: check the required gripping force (10 to 20 times the workpiece weight is recommended), the gripping point distance, and the external force on the fingers. Replacement seal kit for the 32 mm size is MHS32-PS; fingers are ordered as a set of three.

Installation & Maintenance

• The body can be mounted from two directions using tapped holes or through holes, with positioning pin holes for accurate location.
• Keep finger attachments short and light; long attachments reduce the effective force and increase moment on the fingers.
• Install speed controllers so the fingers do not strike the workpiece; supply clean, dry air.
• Lubrication is not required; periodically check finger play and replace seals with the MHS32-PS kit when leakage appears.

Typical Applications in Oman & the GCC

The MHS3-32D is well suited to robot end effectors and pick-and-place heads handling bottle caps, flanges, bearings, valve bodies, turned bushes and pipe fittings – tasks common in packaging, oil and gas component workshops and general manufacturing across the region.

Why Source from Seven Star LLC

Seven Star LLC supplies SMC grippers and pneumatic components across Oman and the GCC. Share the full code, including any auto switch suffix, and our team can help confirm the correct MHS3-32D ordering code before you request a quote.