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Tolerances

APC International, Ltd. provides piezoelectric ceramic elements manufactured to the industry standard tolerance values listed here. We can prepare elements to tighter tolerances on request. Items also are available "as fired," (without an OD, ID, length, or width machining tolerance), when dimensional requirements are not critical.

Common tolerances for electrical / piezoelectric characteristics are:

  • Capacitance: ±20%
  • d33 value: ±20%
  • Frequency: ±5% (Frequency tolerances as tight as ±0.5% are avaliable upon request)

Standard Machining Tolerances for APCI Ceramic Parts

Nominal Value Standard Tolerance (±)
Disc/Ring/Cylinder (Tube): Outer Diameter
<1.000" 0.010"
≥1.000" to <1.500" 0.015"
≥1.500" to <2.000" 0.025"
≥2.000" 0.040"
<25 mm 0.25 mm
≥25 mm to <38 mm 0.38 mm
≥38 mm to <50 mm 0.60 mm
≥50 mm 1.00 mm
Ring/Cylinder (Tube): Inner Diameter
<0.250" 0.010"
≥0.250" to <0.500" 0.015"
≥0.500" to <1.000" 0.020"
≥1.000" 0.025"
<6 mm 0.25 mm
≥6 mm to <13 mm 0.38 mm
≥13 mm to <25 mm 0.50 mm
≥25 mm 0.60 mm
Plate: Length or Width
<0.500" 0.005"
≥0.500" to <1.000" 0.010"
≥1.000" to <1.500" 0.015"
≥1.500" to <2.000" 0.025"
≥2.000" 0.040"
<13 mm 0.13 mm
≥13 mm to <25 mm 0.25 mm
≥25 mm to 38 mm 0.38 mm
≥38 mm to <50 mm 0.60 mm
≥50 mm 1.00 mm
All Parts: Thickness
0.008" to <0.200" 0.001"
≥0.200" 0.002"
0.20 mm to <5.00 mm 0.025 mm
≥5.00 mm 0.05 mm

Permissible Irregularities

Irregularity
Linear Std. Dimen.
Allowable Size
Linear Metric Dimen.
Allowable Size
Physical Chips
<0.250" ≤0.040" <6.35mm ≤1.00mm
≥0.250" <0.500" ≤0.080" ≥6.35mm <13.00mm ≤2.00mm
≥0.500" <1.000"
≤0.100" ≥13.00mm <25.00mm ≤2.50mm
≥1.000" ≤0.125" ≥25.00mm ≤3.17mm
Silver Flaws Total combined area of silver flaws is not to exceed 0.5% of total electrode area
Cracks Parts are to be free of cracks
Standard physical inspections are performed with no magnification, roughly 12" from workspace

We will attach electrical leads on request. Common leads are:

  • 26AWG to 32AWG / ranging from 2" to 6" in length
  • Stock size is 32AWG / 6" in length
  • Other sizes are available upon request

Please be specific when requesting parts, tolerances, or electrode patterns. Provide drawings or sketches for parts or electrode patterns, and include ID tolerance if requesting rings or cylinders (tubes). For custom electrical leads, please specify AWG and length and provide a drawing showing the desired locations.