Vacuum suction cups for gripping · Cup diameter from load, vacuum and safety factor, horizontal versus vertical pick-up, flat versus bellows shape, material and technical data
A vacuum suction cup is the elastomer cup and connector that seals against a workpiece so that ambient air pressure holds it once the space inside is evacuated; it is the contact element of vacuum grippers, lifters and pick-and-place tools. Settle three things before ordering: the cup diameter and number from the load, vacuum level and pick-up direction with a safety factor, the cup shape for the surface and handling, and the material for the workpiece and environment.
Flat, bellows and special suction cups with fittings for automated grippers, robot end-effectors and vacuum lifters. Vacuum generators and pumps, complete vacuum lifting devices, suction-cup feet for furniture and household suction hooks are outside this page; vacuum generators and robot grippers have their own pages.
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Schmalz, a vacuum gripping maker, explains that ambient pressure presses the cup against the workpiece once the pressure inside the cup is lower, and that holding force is F = Δp × A — the pressure difference times the effective suction area — as a purely static value without safety factor. It recommends a safety factor S of at least 2, notes that Germany's accident prevention regulation (UVV) prescribes a binding factor of 1.5, and says swivelling workpieces needs 2.5 or more because of the turning forces. [1] [2]
Its sizing formula is d = 1.12 × √(m × S ÷ (P × n)), with d the cup diameter in cm, m the workpiece mass in kg, P the vacuum in bar and n the number of cups; for vertical pick-up the denominator also includes the friction coefficient μ, which Schmalz says must be measured for the actual surface (dry, moist or oily). In its examples a 50 kg workpiece on four cups at 0.4 bar with S = 2 leads to a PFYN 95 (95 mm) cup for horizontal pick-up, but a PFYN 150 (150 mm) cup for vertical pick-up with a measured μ of 0.5. [1]
Editorial calculation: the horizontal case gives 1.12 × √(100 ÷ 1.6) ≈ 8.9 cm and the vertical case 1.12 × √(100 ÷ 0.8) ≈ 12.5 cm, which Schmalz rounds up to its PFYN 95 and PFYN 150 cups. A 20 kg part swivelled on two cups at 0.6 bar with S = 2.5 would need about 1.12 × √(50 ÷ 1.2) ≈ 7.2 cm, before applying μ for any vertical load. [1]
Editorial note: these are static values; acceleration, porous or flexible workpieces and leaks reduce real holding force, which Schmalz addresses through the safety factor and suction trials for porous parts. [1]
Give the supplier the workpiece material, surface (smooth, rough, oily, porous), mass and dimensions, temperature, pick-up direction and motion (accelerations, swivelling), number of cups and spacing, vacuum level and generator, cycle time, any marking or food-contact requirement, fitting thread and quantity.
02
Schmalz describes flat suction cups as suited to flat or slightly curved surfaces, with low inner volume for fast evacuation, good stability for high shear forces and positioning accuracy — used for sheet metal, cardboard, glass, plastic parts and wooden boards in short-cycle automation. Bellows suction cups compensate for height differences, adapt to uneven or curved surfaces and pick fragile parts gently — used for body panels, tubes, electronic components, injection-moulded parts and shrink-wrapped packs. [3]
Its technical-data guide says catalogue values are based on a vacuum of −0.6 bar and a dry or lubricated surface, without safety factor. Theoretical suction force is calculated perpendicular to the surface; shear force (tangential) and tearing force are measured. It also lists the minimum radius of curvature that can be gripped, the stroke during evacuation and the inner volume used to calculate evacuation time. [4] It says abrasion resistance, oil resistance and food safety are set by choosing the cup material. [5]
Linked suppliers list vacuum suction cups for automation, glass and panel lifters, and rubber and silicone suction cups moulded to customer designs. [6] [7]
03
The listings reviewed range from automation suction cups and vacuum gripping systems to glass-lifter cups and moulded rubber or silicone cups; ask each for diameter, material, suction and shear force at a stated vacuum, inner volume and fitting options.
04
Inner volume sets evacuation time, while the lip and the flat or bellows body decide which surfaces the cup can seal on and how much height difference it can take up. [4] [3]
| Part | Role | Fix in the order |
|---|---|---|
| Sealing lip | Seals on the surface; effective area. [1] [3] | Diameter; lip shape. |
| Body or bellows | Stiffness, stroke, height compensation. [3] [4] | Flat or bellows. |
| Elastomer material | Abrasion, oil, food contact. [5] | Material. |
| Lip profile | Round, oval, steep or flat levelling lip. [3] | Lip type. |
| Connecting fitting | Joins cup to gripper. [2] | Thread; size. |
| Inner volume | Sets evacuation time. [4] | Volume. |
05
Catalogue suction and shear forces are stated without a safety factor, so compare them only after applying the factor from the sizing section. [4] [1]
| Field | What it means and published values | Ask the supplier for |
|---|---|---|
| Suction Force (N) | F = Δp × A, static; catalogue values at −0.6 bar. [1] [4] | Suction and shear force. |
| Cup Diameter (mm) | From d = 1.12 × √(m × S ÷ (P × n)). [1] | Diameter. |
| Vacuum Level (kPa) | Catalogue basis −0.6 bar (−60 kPa). [4] | Rated vacuum. |
| Operating Temperature (°C) | Material limit. [5] | Range. |
| Ingress Protection | Rating if a sensor or valve is fitted. | If specified. |
| Material | Chosen for abrasion, oil, food safety. [5] | Material; hardness. |
| Weight (kg) | Per cup. | Weight. |
| Repeatability (mm) | Flat cups give positioning accuracy. [3] | Value. |
| Air Consumption (L/min) | Set by generator and leakage. [1] | Volume flow needed. |
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Paste it into your enquiry below or into an email to a maker, then replace every bracket.
Workpiece: [material; surface; mass; size] Handling: [horizontal; vertical; swivel; accelerations] Cups: [number; spacing] Vacuum: [level; generator] Shape: [flat; bellows; special] Material: [requirements; food contact] Fitting: [thread; size] Quantity: [per size]
HanTian Automation lists cups within a vacuum gripping range; Jinan PLK and Jinan Yidao list glass suction cups and lifters; Qingdao Jinyuan and Xiamen Better Silicone mould rubber and silicone cups; Wuxi XinTong lists them alongside hot press platens.
Lists vacuum suction cups within its vacuum gripping and automation range.
Product scope checked 2026-10-11
Lists suction cups and electric vacuum suction-cup glass lifters.
Product scope checked 2026-10-11
Lists glass suction cups.
Product scope checked 2026-10-11
Lists moulded rubber vacuum suction cups.
Product scope checked 2026-10-11
Lists silicone vacuum suction cups among moulded silicone parts.
Product scope checked 2026-10-11
Lists vacuum suction cups alongside hot press platens.
Product scope checked 2026-10-11
Explore company information and manufacturing capabilities, then discuss the scope of your project with a relevant supplier.
Schmalz uses d = 1.12 × √(m × S ÷ (P × n)) in cm, dividing by μ as well for vertical pick-up. [1]
Schmalz recommends at least 2, notes 1.5 is binding under Germany's UVV, and 2.5 or more when swivelling. [1]
Schmalz recommends bellows cups for height differences, uneven or curved surfaces and fragile parts. [3]
Schmalz bases its catalogue values on −0.6 bar without a safety factor. [4]
Sources checked 2026-10-11. Schmalz is a vacuum gripping maker publishing know-how pages on suction cup sizing, shapes, materials and technical data; HanTian and PLK are linked suppliers.
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