Squeegee blade and holder assembly for SMT stencil printers (metal and polyurethane blades)
Blade and holder for an SMT stencil printer · 0.007 to 0.012 in metal blades and how far they bend, holder angle against attack angle, 70 or 90 Shore A urethane, blade length per printer, side dams and coatings
A squeegee assembly is the replaceable blade-and-holder unit fitted to a stencil printer's print head: a thin spring-steel or polyurethane blade clamped or bonded into a holder that sets its contact angle, on some designs with side dams that keep the paste roll on the stencil. The printer supplies the force and speed; the assembly decides how the blade bends under that force and therefore the angle at which paste is pushed into the apertures. Check three things first: blade material and thickness, the holder angle and how far the blade will deflect from it during the stroke, and a blade length that matches the printer's head and the board width.
Squeegee blades and holder assemblies for SMT solder paste stencil printers: metal blade thickness and coatings, polyurethane blade hardness, contact and attack angle, blade length and holder fit per printer make, side dams and paste retainers. Complete manual, semi-automatic and automatic stencil printers, their paste settings and machine accuracy are covered on the Solder paste printer page. Enclosed print heads, floor-scrubber squeegees and screen-printing squeegees for graphics are outside this page.
CNFX editorial research · Sources checked October 12, 2026 · 4 sources
0.007, 0.008, 0.010 or 0.012 in: how metal blade thickness changes the bend and the fill
Rita Mohanty and colleagues at Speedline Technologies and Cookson Electronics measured eight metal blades in a holder fitted with a force dial and modelled the bending with the Euler small-deflection equation d = F·L³/3EI, with I = w·t³/12. The 0.007 in blade deflected further, and so ran at a different attack angle, than the 0.010 in blades; a 0.010 in coated blade of softer steel showed more static deflection than a 0.010 in stainless blade, but similar deflection while printing. [1]
Printing a 5 mil (0.127 mm) laser-cut stencil with area ratios from 1.5 down to 0.5 on an MPM Accela, the team found print pressure the leading factor for the 0.010 in blade and print speed the leading factor for the 0.007 in blade; on square apertures, the hardest shape to fill, 0.007 in blades from two vendors gave slightly higher transfer efficiency with lower standard deviation, and a flatter deposit. [1]
Editorial calculation: with the same free length, force and steel, deflection scales with 1/t³, so a 0.007 in blade bends (0.010 ÷ 0.007)³ ≈ 2.9 times as far as a 0.010 in blade. In millimetres, 0.007, 0.008, 0.010 and 0.012 in are 0.178, 0.203, 0.254 and 0.305 mm. [1]
Transition Automation offers its Permalex replacement blades, 32 mm wide, in 0.010 in, which it marks as recommended, and 0.008 in, marked special fine, with the coating either on the edge only or on the whole blade; its Slim-Line Pro listing assigns edge-coated blue spring steel to solvent-based paste and the whole-blade coating to water-based paste. [4] Mohanty reports a blade hardness of about 75–80 on the Rockwell A scale as effective for a clean stencil and the desired deflection angle, and that smoother blade surfaces hold less paste. [2]
Give the supplier the printer make and model, stencil thickness, the smallest area ratio on the stencil, the paste chemistry (solvent-based or water-based), and whether you want a 0.010 in or a thinner blade, coated on the edge or the whole blade.
02
Holder angle is not attack angle: what the blade does under force
Mohanty distinguishes the contact angle the holder sets before the stroke from the attack angle the blade takes under print pressure and speed, and states that the attack angle is what controls print quality. Studies she cites found that, on average, an attack angle of 50°–60° gave more repeatable deposits than 30°–45°, and that paste does not start filling an aperture until the paste roll has travelled at least 75% beyond its start; the Speedline team's working hypothesis is that a thinner, more compliant blade starts the filling earlier. [2][1]
George Babka's tests at Yamaha's Hamamatsu laboratory used 350 mm stainless steel blades on a Yamaha YGP printer whose head changes blade angle by servo. Varying the angle from 45° to 65° changed the paste filling pressure; lower angles flattened the roll and raised the peak pressure. Doubling squeegee force from 50 to 100 N barely changed paste pressure, equivalent to a 0.62° change in angle (to 54.38° from 55°). [3]
Editorial calculation: on the 350 mm blade, 50 N and 100 N are 50 ÷ 350 ≈ 0.14 N/mm and 100 ÷ 350 ≈ 0.29 N/mm of blade length. [3] Babka concludes that the minimum force that wipes the stencil clean should be used, and that the angle has to be changed by the holder or the head rather than by force. [3]
Babka also notes that on a two-blade head the paste that sticks to the first blade is missing from the return stroke, so print quality can differ between the two directions, and that a durable low-friction blade finish reduces the effect. [3]
03
Blade length, urethane hardness and side dams by printer make
Squeegee assemblies are built to the print head they clip into, so the order starts from the printer model, then the length.
Transition Automation's holders include articulating 'Soft-Touch' side dams or paste retainers to keep the paste contained and protect the stencil; its PolyMAX urethane assemblies are offered for glue, resin, flux or solder paste where stepped stencils are specified. [4] Mohanty reports that polyurethane blades of 90–110 durometer have printed successfully, but that metal blades give a more controlled print height across the board for dense boards and small components. [2][1]
Editorial note: the listings give lengths without a unit; they read as millimetres, since 152, 203 and 305 match 6, 8 and 12 in. Ask for the length that covers the board's printed area on your printer rather than the longest the head accepts.
Explore company information and manufacturing capabilities, then discuss the scope of your project with a relevant supplier.
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Compiled and source-reviewed by the CNFX editorial team.
Each manufacturer above links to the page on that company's own website where the product is listed, with the date we checked it. How we source and review
· Page last updated 13 October 2026
Buyer questions
Is a thinner squeegee blade better for fine-pitch printing?
In Speedline and Cookson tests on a 5 mil stencil, 0.007 in blades gave slightly higher transfer efficiency and lower variation on square apertures than 0.010 in blades. [1]
Does more squeegee force change the blade angle?
Hardly: in Yamaha tests with a 350 mm stainless blade, doubling force from 50 to 100 N corresponded to a 0.62° angle change. [3]
What hardness are polyurethane SMT squeegees?
Transition Automation's PolyMAX urethane blades are 70 or 90 Shore A; Mohanty cites 90–110 durometer polyurethane blades. [4][2]
What is the difference between contact angle and attack angle?
Contact angle is set by the holder before the stroke; attack angle is the angle the blade takes under pressure and speed, and it is the one that affects print quality. [1][2]
Sources and what still needs a direct check
Sources checked 2026-10-12. Two of the sources are by the same Speedline author, one as a trade-magazine column and one as an IPC conference paper with the test data; the Yamaha tests come from a separate Circuits Assembly article. Transition Automation data are its own product listings.
