diff --git a/pandas/io/formats/format.py b/pandas/io/formats/format.py
index c6c09c2636852..726de09b60d70 100644
--- a/pandas/io/formats/format.py
+++ b/pandas/io/formats/format.py
@@ -1748,16 +1748,15 @@ def __init__(
         self,
         values: TimedeltaArray,
         nat_rep: str = "NaT",
-        box: bool = False,
         **kwargs,
     ) -> None:
+        # TODO: nat_rep is never passed, na_rep is.
         super().__init__(values, **kwargs)
         self.nat_rep = nat_rep
-        self.box = box
 
     def _format_strings(self) -> list[str]:
         formatter = self.formatter or get_format_timedelta64(
-            self.values, nat_rep=self.nat_rep, box=self.box
+            self.values, nat_rep=self.nat_rep, box=False
         )
         return [formatter(x) for x in self.values]
 
diff --git a/pandas/tests/io/formats/test_format.py b/pandas/tests/io/formats/test_format.py
index fe6ddd3aeb1d4..51965f753a0fb 100644
--- a/pandas/tests/io/formats/test_format.py
+++ b/pandas/tests/io/formats/test_format.py
@@ -3187,49 +3187,49 @@ def test_all(self):
 class TestTimedelta64Formatter:
     def test_days(self):
         x = pd.to_timedelta(list(range(5)) + [NaT], unit="D")._values
-        result = fmt._Timedelta64Formatter(x, box=True).get_result()
-        assert result[0].strip() == "'0 days'"
-        assert result[1].strip() == "'1 days'"
+        result = fmt._Timedelta64Formatter(x).get_result()
+        assert result[0].strip() == "0 days"
+        assert result[1].strip() == "1 days"
 
-        result = fmt._Timedelta64Formatter(x[1:2], box=True).get_result()
-        assert result[0].strip() == "'1 days'"
+        result = fmt._Timedelta64Formatter(x[1:2]).get_result()
+        assert result[0].strip() == "1 days"
 
-        result = fmt._Timedelta64Formatter(x, box=False).get_result()
+        result = fmt._Timedelta64Formatter(x).get_result()
         assert result[0].strip() == "0 days"
         assert result[1].strip() == "1 days"
 
-        result = fmt._Timedelta64Formatter(x[1:2], box=False).get_result()
+        result = fmt._Timedelta64Formatter(x[1:2]).get_result()
         assert result[0].strip() == "1 days"
 
     def test_days_neg(self):
         x = pd.to_timedelta(list(range(5)) + [NaT], unit="D")._values
-        result = fmt._Timedelta64Formatter(-x, box=True).get_result()
-        assert result[0].strip() == "'0 days'"
-        assert result[1].strip() == "'-1 days'"
+        result = fmt._Timedelta64Formatter(-x).get_result()
+        assert result[0].strip() == "0 days"
+        assert result[1].strip() == "-1 days"
 
     def test_subdays(self):
         y = pd.to_timedelta(list(range(5)) + [NaT], unit="s")._values
-        result = fmt._Timedelta64Formatter(y, box=True).get_result()
-        assert result[0].strip() == "'0 days 00:00:00'"
-        assert result[1].strip() == "'0 days 00:00:01'"
+        result = fmt._Timedelta64Formatter(y).get_result()
+        assert result[0].strip() == "0 days 00:00:00"
+        assert result[1].strip() == "0 days 00:00:01"
 
     def test_subdays_neg(self):
         y = pd.to_timedelta(list(range(5)) + [NaT], unit="s")._values
-        result = fmt._Timedelta64Formatter(-y, box=True).get_result()
-        assert result[0].strip() == "'0 days 00:00:00'"
-        assert result[1].strip() == "'-1 days +23:59:59'"
+        result = fmt._Timedelta64Formatter(-y).get_result()
+        assert result[0].strip() == "0 days 00:00:00"
+        assert result[1].strip() == "-1 days +23:59:59"
 
     def test_zero(self):
         x = pd.to_timedelta(list(range(1)) + [NaT], unit="D")._values
-        result = fmt._Timedelta64Formatter(x, box=True).get_result()
-        assert result[0].strip() == "'0 days'"
+        result = fmt._Timedelta64Formatter(x).get_result()
+        assert result[0].strip() == "0 days"
 
         x = pd.to_timedelta(list(range(1)), unit="D")._values
-        result = fmt._Timedelta64Formatter(x, box=True).get_result()
-        assert result[0].strip() == "'0 days'"
+        result = fmt._Timedelta64Formatter(x).get_result()
+        assert result[0].strip() == "0 days"
 
 
-class Test_Datetime64Formatter:
+class TestDatetime64Formatter:
     def test_mixed(self):
         x = Series([datetime(2013, 1, 1), datetime(2013, 1, 1, 12), NaT])._values
         result = fmt._Datetime64Formatter(x).get_result()